Polyol ether derivatives and production methods therefor

ABSTRACT

Polyol ether derivatives, a method for producing the polyol ether derivatives, and a working fluid composition for a refrigerating machine containing a hydrofluorocarbon and a refrigeration oil containing the polyol ether derivatives as a base oil.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to polyol ether derivatives which areuseful as polar oils, organic solvents, lubricants, syntheticlubricating oils, or refrigeration oils, or as intermediates in theproduction of the above oils, etc.; and to a method for producing thepolyol ether derivatives; and also to a working fluid composition for arefrigerating machine using the above polyol ether derivatives as a baseoil. Here, the term "polyol ether" means a partially etherified polyol.

2. Discussion of the Related Art

Recently, the use of dichlorodifluoromethane (CFC12) for refrigeratorsand car air conditioners has been restricted, and will be legally bannedin order to protect the ozone layer. Also, the use ofchlorodifluoromethane (HCFC22) for room air conditioners is about to belegally regulated. Thus, hydrofluorocarbons which do not destroy theozone layer, such as 1,1,1,2-tetrafluoroethane (HFC 134a),difluoromethane (HFC32), and pentafluoroethane (HFC125), have beendeveloped as substitutes for CFC12 or HCFC22.

However, since the polarity of hydrofluorocarbons is higher than that ofCFC12 or HCFC22, the use of conventional lubricating oils, such asnaphthenic mineral oils, poly-α-olefins, or alkylbenzenes, causestwo-layer separation of the working fluid at low temperatures. This isdue to poor compatibility between the conventional lubricating oils andhydrofluorocarbons. Two-layer separation hampers oil return, which inturn interferes with heat transfer due to deposition of a thick oil filmon a heat transfer surface of the condenser and evaporator used as heatexchangers. It can also cause significant failures, such as poorlubrication, and foaming upon starting operation. Therefore, theconventional refrigeration oils cannot be used as refrigeration oilsunder these new refrigerant atmospheres.

As for lubricity, CFC12 and HCFC22 generate hydrogen chloride uponpartial decomposition. The hydrogen chloride thus formed reacts with thefriction surface to form a coating of chlorides, thereby improving thelubricity. On the other hand, non chlorine containing hydrofluorocarbonsare not expected to have such an effect; therefore, refrigeration oilsused in combination with hydrofluorocarbons are required to have afurther excellent lubricity when compared to the conventionalrefrigeration oils.

In addition, the refrigeration oils used in combination withhydrofluorocarbons have to have good thermal stability in the presenceof hydrofluorocarbons.

Moreover, with compression-type refrigerating machines for electricrefrigerators and air conditioners, since organic materials are used formotor components, such as insulators and enameled wires, the workingfluid comprising a hydrofluorocarbon and a refrigeration oil is requiredto have no adverse effects on these organic materials and also have agood insulating property.

Refrigeration oils which can be used in combination withhydrofluorocarbons, such as 1,1,1,2-tetrafluoroethane (HFC134a),disclosed in U.S. Pat. No. 4,755,316 and Japanese Patent Laid-Open No.2-129294, are ether compounds of polyalkylene glycols (hereinafterabbreviated as PAG-OH) prepared by the addition of an alkylene oxide toa polyhydric alcohol which is not alkyl-capped at the terminal hydroxyl.As an example of the polyhydric alcohols used, the former disclosestrimethylol propane and the latter discloses glycerol.

In order to solve various problems of the above compounds, such as poorcompatibility with HFC and high hygroscopicity, compounds prepared byalkyl-capping the terminal hydroxyl groups of the above ether compounds(hereinafter abbreviated as PAG) are disclosed in Japanese PatentLaid-Open Nos. 3-14894, 3-205492, 4-20596, 4-359996, and 5-98275.

Since PAG-OH and PAG have a higher polarity than the naphthenic mineraloils, their compatibility with HFC134a at low temperatures is good.However, PAG-OH and PAG phase-separate as the temperature increases asmentioned in U.S. Pat. No. 4,755,316. There are also several problemswith these compounds. For example, a poor insulating property is one ofthe problems. Due to this significant problem, PAG-OH and PAG cannot beused for a refrigerating device of electric refrigerators and airconditioners where a motor is incorporated in a compressor. Therefore,applications of PAG-OH and PAG are proposed for car air conditionerswhere their poor insulating property does not cause any problems. Highhygroscopicity is another significant problem of PAG-OH and PAG. Thewater absorbed by the compounds causes thermal instability of thecompounds in the presence of HFC134a, and hydrolysis of organicmaterials, such as PET films.

In order to solve the above problems of polyether compounds, such aspoor insulating property and high hygroscopicity, ester compounds andcarbonate compounds have been developed. For example, mixed oils ofpolyether oils and ester oils are disclosed in U.S. Pat. No. 4,851,144(corresponding to Japanese Patent Laid-Open No. 2-276894) and JapanesePatent Laid-Open No. 2-158693; ester oils are disclosed in JapanesePatent Laid-Open Nos. 3-505602, 3-128991, and 3-128992; and carbonateoils are disclosed in Japanese Patent Laid-Open Nos. 2-132178 and3-149295, and European Patent No. 421,298. All of the compoundsdisclosed can be used as a refrigeration oil in combination with1,1,1,2-tetrafluoroethane (HFC134a).

Ester compounds and carbonate compounds show good compatibility withhydrofluorocarbons and high thermal stability in the presence ofhydrofluorocarbons. Also, these compounds have markedly betterinsulating properties and much lower hygroscopicity than polyethercompounds.

However, when compared with the conventional CFC12-mineral oil workingfluid system, both freon and oil tend to have a high polarity in thehydrofluorocarbon-ester oil system or hydrofluorocarbon-carbonate oilsystem, and the systems become highly hygroscopic. Particularly, in thesystem using an ester oil, a carboxylic acid is likely to be formedowing to hydrolysis of the ester oil, and the formed carboxylic acid mayin turn corrode and wear down the metals. Also, in the case of using acarbonate oil, there arises such a problem that a non-condensable carbondioxide gas is generated owing to hydrolysis of the carbonate oil tocause a low refrigerating capacity.

In particular, in the case of room air conditioners, it is commonpractice to fill an air conditioner with a refrigerant uponinstallation. Therefore, unlike refrigerating machines for which fillingof refrigerant is carried out in a factory, it is almost impossible toprevent a working fluid of room air conditioners from being contaminatedwith water. Therefore, there has been a concern about the reliability ofthe hydrofluorocarbon-ester oil system and hydrofluorocarbon-carbonateoil system, when used in room air conditioners.

W093/24435 discloses that a polyvinyl ether compound having goodcompatibility with hydrofluorocarbons and good insulating property isprepared by polymerization of vinyl ether monomers and subsequenthydrogenation. However, since the polyvinyl ether compound issynthesized by polymerization, it shows molecular weight distribution.Therefore, a part of high molecular weight polymers sometimes causesplugged capillaries of refrigerating machines and worsens thecompatibility of the compound with hydrofluorocarbons. Also, thecompound requires complicated post-treatment and cannot always beobtained in high yield because the vinyl ether monomers, the startingmaterials of the polyvinyl ether compound, are not stable substances. Inparticular, the yield of those with a low degree of polymerization(around 6) is low. Some vinyl ether monomers of certain structurescannot be easily obtained, and are, therefore, very expensive.

As mentioned above, polyvinyl ether compounds show molecular weightdistribution. The products with higher molecular weights sometimes causeto impair the performance of the compounds. Polyvinyl ether compoundsalso have drawbacks of limited availability of the starting materialsand poor yields of those with low degrees of polymerization, whichtogether make the product cost expensive.

The refrigerant-oil systems developed so far have various drawbacks asmentioned above. The hydrofluorocarbon-PAG (PAG-OH) oil system hasproblems in hygroscopicity and insulating property; and thehydrofluorocarbon-ester oil system and the hydrofluorocarbon-carbonateoil system have problems of poor hydrolysis resistance. Both of thesesystems are unsatisfactory as a working fluid composition for arefrigerating machine, because, as compared with the conventionalCFC12-mineral oil system, they have higher hygroscopicity, lower thermalstability, stronger deteriorating action on organic materials, andstronger effects to corrode and wear metals. Polyvinyl ether compoundsshow a molecular weight distribution and the molecules with highmolecular weights cause to lower the compatibility withhydrofluorocarbons. Polyvinyl ether compounds also have drawbacks oflimited availability of the starting materials and of high cost.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide novelpolyol ether derivatives that can make an inexpensive base oil for aworking fluid composition for a refrigerating machine, the novel polyolether derivatives having excellent compatibility withhydrofluorocarbons, high thermal stability, strong resistance againsthydrolysis, appropriate kinematic viscosity, good fluidity at lowtemperatures, and especially good volume resistivity, thereby solvingthe above problems.

It is another object of the present invention to provide a method bywhich the above polyol ether derivatives are industrially advantageouslyproduced.

It is still another object of the present invention to provide a workingfluid composition for a refrigerating machine comprising a refrigerationoil containing, as a base oil, the polyol ether derivatives and ahydrofluorocarbon.

Known polyol ether derivatives each having an alcohol residue from ahexahydric alcohol, such as sorbitol and mannitol are hexamethyl ether,hexavinyl ether, hexaoleyl ether, 1,3,4,5,6-pentamethyl ether (monool),2,3,4,5,6-pentabenzyl ether (monool), 1,3,5-trimethyl-6-triphenyl methylether (diol), 1,2,5,6-tetrakistetradecyl ether (diol), 1,4,5-triethylether (triol), 2,3,5-trisdodecyl ether (triol), 1,6-didodecyl ether(tetraol), 2,5-dibenzyl ether (tetraol), 1-t-butyl ether (pentaol), and1-hexadecyl ether (pentaol).

However, polyol ether derivatives having an ether alkyl group (an alkylgroup bound to an oxygen atom) which is branched at α-position, i.e.polyol ether derivatives having secondary or tertiary alkyl groups as anether alkyl group; and polyol ether derivatives having branched etheralkyl groups of 3 to 17 carbon atoms have yet to be known except forthose having t-butyl groups as ether alkyl groups.

As a result of intense research in view of the above objects, thepresent inventors have found that polyol ether derivatives having acertain structure and not having an alkylene oxide group in a moleculecan achieve the above objects.

For producing such polyol ether derivatives, there have been methods inwhich a hexahydric alcohol reacts with an alkylating agent, such as adialkyl sulfate, an alkyl tosylate, and an alkyl halide. The methodshowever have a problem that the desired product cannot be obtained in ahigh yield except when the alkyl of alkylating agent is a primary alkyl,and a problem that by-products such as sulfates and common salt areproduced in high amounts, especially when the degree of etherificationis increased, causing disadvantages in terms of production and economy.

In this situation, the present inventors have found that the polyolether derivatives of the present invention can easily be obtained bycarrying out a reaction of a hexahydric alcohol with a carbonyl compoundto form an intermediate cyclic acetal, and hydrogenating orhydrogenating and alkyl-capping the cyclic acetal to give the polyolether derivatives.

The present invention has been achieved based upon the above findings.

In brief, the present invention is directed to:

(1) A polyol ether derivative represented by any one of the followinggeneral formulas (I) to (IV): ##STR1## wherein R₁ represents a hydrogenatom, a linear alkyl group having 1-21 carbon atoms or a branched alkylgroup having 3-21 carbon atoms; R₂ represents a branched alkyl grouphaving 3-17 carbon atoms when R₁ represents a hydrogen atom, or R₂represents a linear alkyl group having 1-21 carbon atoms or a branchedalkyl group having 3-21 carbon atoms when R₁ represents a linear alkylgroup having 1-21 carbon atoms or a branched alkyl group having 3-21carbon atoms; R₁ and R₂ may together join to form a ring with analkylene group having 2-13 carbon atoms; 2 to 6 pairs of R₁ and R₂ maybe identical or different; k₁ represents a number of 0-5, p₁ representsa number of 0-2, m₁ represents or 1, wherein k₁, p₁ and m₁ satisfy theequation k₁ +(m₁ +2)p₁ =5; k₂ and n₂ each represents a number of 0-4, p₂represents a number of 0-2, m₂ represents 0 or 1, wherein k₂, p₂, m₂ andn₂ satisfy the equation k₂ +(m₂ +2)p₂ +n₂ =4; R₃ represents a hydrogenatom, a linear alkyl group having 1-8 carbon atoms or a branched alkylgroup having 3-8 carbon atoms; and repeating units in formulas (I) and(II), namely methylene groups substituted with oxygen-containing group(hereinafter, simply referred to as O-methylene groups) in the number ofk₁ and cyclic acetal (or ketal) units in the number of p₁ in formula(I), and O-methylene groups in the numbers of k₂ and n₂ and cyclicacetal (or ketal) units in the number of p₂ in formula (II) may bearranged at random or in block form;

(2) The polyol ether derivative described in (1) above, wherein analcohol residue of the polyol ether derivative is derived from sorbitol;

(3) A method for producing a polyol ether derivative represented by anyone of formulas (VII) to (X), comprising the steps of:

reacting a hexahydric alcohol represented by the following formula (V):##STR2## with a carbonyl compound represented by the following formula(VI): ##STR3## wherein R₁ represents a hydrogen atom, a linear alkylgroup having 1-21 carbon atoms or a branched alkyl group having 3-21carbon atoms; and R₂ represents a linear alkyl group having 1-21 carbonatoms or a branched alkyl group having 3-21 carbon atoms, or with areactive derivative thereof, i.e., an acetal or a ketal, in the presenceof an acid catalyst to form a cyclic acetal or a cyclic ketal; and

hydrogenating, and optionally further alkylating the cyclic acetal orthe cyclic ketal to give a polyol ether derivative represented by thefollowing formulas (VII) to (X): ##STR4## wherein R₁ represents ahydrogen atom, a linear alkyl group having 1-21 carbon atoms or abranched alkyl group having 3-21 carbon atoms; R₂ represents a linearalkyl group having 1-21 carbon atoms or a branched alkyl group having3-21 carbon atoms; R₁ and R₂ may together join to form a ring with analkylene group having 2-13 carbon atoms; 2 to 6 pairs of R₁ and R₂ maybe identical or different; k₁ represents a number of 0-5, p₁ representsa number of 0-2, m₁ represents 0 or 1, wherein k₁, p₁ and m₁ satisfy theequation k₁ +(m₁ +2)p₁ =5; k₂ and n₂ each represents a number of 0-4, parepresents a number of 0-2, m₂ represents 0 or 1, wherein k₂, p₂, m₂ andn₂ satisfy the equation k₂ +(m₂ +2)p₂ +n₂ =4; R₃ represents a hydrogenatom, a linear alkyl group having 1-8 carbon atoms or a branched alkylgroup having 3-8 carbon atoms; and repeating units in formulas (VII) and(VIII), namely O-methylene groups in the number of k₁ and cyclic acetal(or ketal) units in the number of p₁ in formula (VII), and O-methylenegroups in the number of k₂ and n₂ and cyclic acetal (or ketal) units inthe number of p₂ in formula (VIII) may be arranged at random or in blockform;

(4) The method described in (3) above, wherein the hexahydric alcoholrepresented by formula (V) is sorbitol;

(5) The method described in (3) or (4) above, wherein, in formulas (VII)to (X), R₁ represents a hydrogen atom and R₂ represents a linear alkylgroup having 1-13 carbon atoms or a branched alkyl group having 3-13carbon atoms, or wherein R₁ and R₂ in formulas (VII) to (X) eachrepresents a linear alkyl group having 1-13 carbon atoms or a branchedalkyl group having 3-13 carbon atoms;

(6) A working fluid composition for a refrigerating machine, comprisinga hydrofluorocarbon and a refrigeration oil containing a polyol etherderivative represented by the following formula (XI) as a base oil:##STR5## wherein R¹ to R⁶ may be identical or different, eachrepresenting a linear alkyl group having 1-14 carbon atoms, a branchedalkyl group having 3-14 carbon atoms or a cyclic alkyl group having 3-14carbon atoms and the total number of carbon atoms of R¹ to R⁶ being 8 to40;

(7) The working fluid composition for a refrigerating machine describedin (6) above, wherein a hexahydric alcohol residue of the compoundrepresented by formula (XI) is derived from sorbitol;

(8) The working fluid composition for a refrigerating machine describedin (6) or (7) above, wherein the compound represented by formula (XI) issynthesized by the steps of:

reacting a hexahydric alcohol represented by the following formula (V):##STR6## with (a) one or more carbonyl compounds represented by thefollowing formula (XII) for ketalization or acetalization: ##STR7##wherein R⁷ represents a hydrogen atom, a linear alkyl group having 1-13carbon atoms, a branched alkyl group having 3-13 carbon atoms or acyclic alkyl group having 3-13 carbon atoms, and R⁸ represents a linearalkyl group having 1-13 carbon atoms, a branched alkyl group having 3-13carbon atoms or a cyclic alkyl group having 3-13 carbon atoms with theproviso that R⁷ and/or R⁸ have at least one hydrogen atom at α-positionto the carbonyl group, and the total number of carbon atoms of R⁷ and R⁸is 1-13; and R⁷ and R⁸ may together join to form a ring with an alkylenegroup having 2-13 carbon atoms, or with (b) reactive derivatives of thecarbonyl compounds (ketal or acetal) for transketalization ortransacetalization to obtain a cyclic ketal or a cyclic acetal;

hydrogenating the cyclic ketal or the cyclic acetal to obtain a polyolether; and

alkylating the polyol ether to give a polyol ether derivative;

(9) The working fluid composition for a refrigerating machine describedin (6) or (7) above, which further comprises one or more compoundsselected from the group consisting of (a) 0.05 to 2.0 parts by weight ofan epoxy compound, (b) 0.01 to 100 parts by weight of an orthoestercompound, (c) 0.01 to 100 parts by weight of acetal or ketal, and (d)0.05 to 5 parts by weight of carbodiimide, each amount of (a) to (d)being based on 100 parts by weight of the polyol ether derivativerepresented by formula (XI);

(10) The working fluid composition for a refrigerating machine describedin (8) above, which further comprises one or more compounds selectedfrom the group consisting of (a) 0.05 to 2.0 parts by weight of an epoxycompound, (b) 0.01 to 100 parts by weight of an orthoester compound, (c)0.01 to 100 parts by weight of acetal or ketal, and (d) 0.05 to 5 partsby weight of carbodiimide, each amount of (a) to (d) being based on 100parts by weight of the polyol ether derivative represented by formula(XI);

(11) A Working fluid composition for a refrigerating machine, comprisinga hydrofluorocarbon and a refrigeration oil containing as a base oil apolyol ether derivative represented by the following formula (XIII_(AA))or (XIII_(BB)): ##STR8## wherein R¹ to R⁶ may be identical or different,each representing a linear alkyl group having 1-14 carbon atoms, abranched alkyl group having 3-14 carbon atoms or a cyclic alkyl grouphaving 3-14 carbon atoms; R⁷ represents an hydrogen atom, or a linearalkyl group having 1-13 carbon atoms, a branched alkyl group having 3-13carbon atoms or a cyclic alkyl group having 3-13 carbon atoms; R⁸represents a linear alkyl group having 1-13 carbon atoms, a branchedalkyl group having 3-13 carbon atoms or a cyclic alkyl group having 3-13carbon atoms; R⁷ and R⁸ may together join to form a ring with analkylene group having 2-13 carbon atoms; the total number of carbonatoms is 8-40 for R¹, R², R³, R⁶, R⁷ and R⁸ in formula (XIII_(AA)), andfor R¹, R⁴, R⁵, R⁶, R⁷ and R⁸ in formula (XIII_(BB)), and is 1-13 for R⁷and R⁸ in formulas (XIII_(AA) and XIII_(BB)); and "a" to "e" are symbolsfor structure unit, and may be arranged in any sequential order;

(12) The working fluid composition for a refrigerating machine describedin (11) above, wherein a hexahydric alcohol residue of the compoundrepresented by formula (XIII_(AA)) or (XIII_(BB)) is derived fromsorbitol;

(13) The working fluid composition for a refrigerating machine describedin (11) or (12) above, wherein the compound represented by formula(XIII_(AA)) or (XIII_(BB)) is synthesized by the steps of:

reacting a hexahydric alcohol represented by the following formula (V):##STR9## with (a) one or more carbonyl compounds represented by thefollowing formula (XII) for ketalization or acetalization: ##STR10##wherein R⁷ represents a hydrogen atom, a linear alkyl group having 1-13carbon atoms, a branched alkyl group having 3-13 carbon atoms or acyclic alkyl group having 3-13 carbon atoms, and R⁸ represents a linearalkyl group having 1-13 carbon atoms, a branched alkyl group having 3-13carbon atoms, or a cyclic alkyl group having 3-13 carbon atoms with theproviso that R⁷ and/or R⁸ have at least one hydrogen atom at α-positionto the carbonyl group, and the total number of carbon atoms of R⁷ and R⁸is 1-13; and R⁷ and R⁸ may together join to form a ring with an alkylenegroup having 2-13 carbon atoms; or with (b) reactive derivatives of thecarbonyl compounds (ketal or acetal) thereof for transketalization ortransacetalization to obtain a cyclic ketal or a cyclic acetal;

hydrogenating the cyclic ketal or the cyclic acetal to obtain a polyolether ketal or a polyol ether acetal; and

alkylating the polyol ether ketal or the polyol ether acetal;

(14) The working fluid composition for a refrigerating machine describedin (11) or (12) above, which further comprises one or more compoundsselected from the group consisting of (a) 0.05 to 2.0 parts by weight ofan epoxy compound, (b) 0.01 to 100 parts by weight of an orthoestercompound, (c) 0.01 to 100 parts by weight of an acetal or a ketal, and(d) 0.05 to 5 parts by weight of carbodiimide, each amount of (a) to (d)being based on 100 parts by weight of the polyol ether derivativerepresented by formula (XIII_(AA)) or (XIII_(BB));

(15) The working fluid composition for a refrigerating machine describedin (13) above, which further comprises one or more compounds selectedfrom the group consisting of (a) 0.05 to 2.0 parts by weight of an epoxycompound, (b) 0.01 to 100 parts by weight of an orthoester compound, (c)0.01 to 100 parts by weight of an acetal or a ketal, and (d) 0.05 to 5parts by weight of carbodiimide, each amount of (a) to (d) being basedon 100 parts by weight of the polyol ether derivative represented byformula (XIII_(AA)) or (XIII_(BB));

(16) The working fluid composition for a refrigerating machine describedin (6) or (11) above, wherein the polyol ether derivative has an averagemolecular weight in the range of from 200 to 800;

(17) The working fluid composition for a refrigerating machine describedin (6) or (11) above, wherein the polyol ether derivative has an averagemolecular weight in the range of from 300 to 700;

(18) The working fluid composition for a refrigerating machine describedin (6) or (11) above, wherein the polyol ether derivative has aviscosity at 100° C. of from 0.5 to 30 mm² /s; and

(19) The working fluid composition for a refrigerating machine describedin (6) or (11) above, wherein the polyol ether derivative has aviscosity at 40° C. of from 1 to 300 mm² /s.

According to the present invention, novel and useful polyol etherderivatives usable for preparation of synthetic lubricating oils andother various purposes can be produced from inexpensive startingmaterials by simple process.

A working fluid composition for a refrigerating machine comprising ahydrofluorocarbon and a refrigeration oil containing as a base oil novelpolyol ether derivative of the present invention has the followingexcellent properties: good compatibility, good thermal stability, highhydrolysis resistance, adequate kinematic viscosity, good fluidity atlow temperatures, and noticeably high volume resistivity. Thus, aworking fluid composition for a refrigerating machine of the presentinvention can suitably be used for motor-integrated compressionrefrigerating machines used for refrigerators and room air conditioners.

DETAILED DESCRIPTION OF THE INVENTION

Here, for the sake of convenience, the present invention will bedescribed in more detail according to the following three parts: (1)Novel polyol ether derivatives; (2) A novel method for producing polyolether derivatives; and (3) A working fluid composition for arefrigerating machine comprising a refrigeration oil containing as abase oil polyol ether derivatives and a hydrofluorocarbon. In thepresent specification, substituent groups in the formulas are definedfor each formula. Therefore, it should be noted that the definition forR₂, for example, is different between formulas (I)-(IV) and formulas(VI)-(X) and that it is interpreted differently between these two groupsof formulas. Also, it should be noted that superior figures (e.g., R²)in formulas (XI), (XIII_(AA)) and (XIII_(BB)) are used to clearlyindicate that these substituents are defined differently from those inthe other formulas (i.e., formulas (I) to (IV) and (VI) to (X)) whereinferior figures (e.g., R₂) are used.

(1) Novel polyol ether derivatives

The novel polyol ether derivatives of the present invention arerepresented by any one of formulas (I) to (IV).

In formulas (I) to (IV), R₁ represents a hydrogen atom, a linear alkylgroup having 1-21 carbon atoms or a branched alkyl group having 3-21carbon atoms. Examples of the linear alkyl groups having 1-21 carbonatoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl,octyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecyl, nonadecyl, andheneicosyl; and examples of branched alkyls having 3-21 carbon atomsinclude 1-methyloctadecyl, 1-decylundecyl, and 2-methyleicosyl inaddition to the branched alkyls having 3-17 carbon atoms exemplifiedbelow.

In formulas (I) to (IV), when R₁ represents a hydrogen atom, R₂represents a branched alkyl having 3-17 carbon atoms, preferably 3-12carbon atoms. Branched alkyls having 3-17 carbon atoms represented by R₂are exemplified below.

Examples of α-methyl-branched alkyls include isopropyl, 1-methylpropyl,1-methylbutyl, 1-methylpentyl, 1-methylhexyl, 1-methylheptyl,1-methyloctyl, 1-methylnonyl, 1-methyldecyl, 1-methylundecyl, and1-methylhexadecyl.

Examples of other α-branched alkyls include 1-ethylpropyl, 1-ethylbutyl,1-ethylpentyl, 1-propylbutyl, 1-ethylhexyl, 1-propylpentyl,1-ethylheptyl, 1-propylhexyl, 1-butylpentyl, 1-pentylhexyl,1-hexylheptyl, 1-octylnonyl, and 1-hexylundecyl. Examples of cyclicalkyls branched at α-position include cyclopentyl, cyclohexyl,3-(2',2',5'-trimethylcyclohexyl)propyl, and 1-cyclohexylmethyl.

Examples of α- and other polybranched alkyls having one or more branchesat positions other than α-position include 1,2-dimethylpropyl,1,2-dimethylbutyl, 1,3-dimethylbutyl, 1-ethyl-2-methylpropyl,diisopropylmethyl, 1,4-dimethylpentyl, 1-isopropylbutyl,1,3,3-trimethylbutyl, 1,5-dimethylhexyl, 1-ethyl-2-methylpentyl,1-butyl-2-methylpropyl, 1-ethyl-3-methylpentyl, diisobutylmethyl, and1,5,9-trimethyldecyl.

Examples of β-branched alkyls include 2-methylpropyl, 2-methylbutyl,2-methylpentyl, 2-ethylbutyl, 2-methylhexyl, 2-ethylpentyl,2-methylheptyl, 2-ethylhexyl, and 2-propylpentyl.

Examples of β- and other polybranched alkyls having one or more branchesat positions other than α- and β-positions include 2,3-dimethylbutyl,2,4,4-trimethylpentyl, and 2-isopropyl-5-methylhexyl.

Examples of other branched alkyls having one or more branches atpositions other than α- and β-positions include 3-methylbutyl,3-methylpentyl, 4-methylpentyl, 3,3-dimethylbutyl, 3-methylhexyl,4-methylhexyl, 5-methylhexyl, 3,5,5-trimethylhexyl, isodecyl,3,7-dimethyloctyl, and isoheptadecyl.

Examples of alkyls having a tertiary carbon with no hydrogen atom atβ-position include 2,2-dimethylpropyl, 2,2-dimethylbutyl,2,2-dimethylbutyl, 1,2,2-trimethylpropyl, 1-ethyl-2,2-dimethylpropyl,2,2-dimethylpentyl, and 2,3-dimethyl-2-isopropylbutyl.

In formulas (I) to (IV), when R₁ represents a linear alkyl group having1-21 carbon atoms or a branched alkyl group having 3-21 carbon atoms, R₂represents a linear alkyl group having 1-21 carton atoms or a branchedalkyl group having 3-21 carbon atoms. Preferably, R₁ and R₂independently represent a linear alkyl group having 1-12 carbon atoms ora branched alkyl group having 3-12 carbon atoms. Examples of the linearalkyl groups having 1-21 carbon atoms represented by R₂ are the same asthose exemplified above for R₁.

Alternatively, R₁ and R₂ may together join to form a ring with analkylene group having 2-13 carbon atoms. Examples of alkylene groupsinclude ethylene, trimethylene, tetramethylene, pentamethylene,hexamethylene, 1-methyltetramethylene, 2-methyltetramethylene,1-methylpentamethylene, 2-methylpentamethylene, 3-methylpentamethylene,1,3-dimethylpentamethylene, 1,5-dimethylpentamethylene,2,2,4-trimethylpentamethylene, 1-tert-butylpentamethylene,3-tert-butylpentamethylene, 1-isopropyl-3-methylpentamethylene, andnonamethylene groups. Examples of linear alkyl group having 1-8 carbonatoms or a branched alkyls having 3-8 carbon atoms represented by R₃include methyl, ethyl, propyl, butyl, isobutyl, hexyl, and 2-ethylhexyl,with a preference given to methyl or ethyl.

Of the polyol ether derivatives represented by formulas (I) to (IV),those of which alcohol residue is derived from sorbitol are preferable.

The following are examples (compound names and structures) of polyolether derivatives represented by formulas (I) to (IV), but the presentinvention are not limited to the examples:

1,6-di-O-(1-methylethyl)sorbitol ##STR11##2,4,5-tri-O-methyl-1,3,6-tri-O-(3,5,5-trimethylhexyl)sorbitol ##STR12##(R: 3,5,5-trimethylhexyl group)1,6-di-O-(1-methylbutyl)-3,4-O-(1-methylbutylidene)sorbitol ##STR13##(2) Novel method for producing polyol ether derivatives

A method of the present invention comprises the steps of reacting ahexahydric alcohol represented by formula (V) with a carbonyl compound(ketone or aldehyde) or with a reactive derivative thereof (ketal oracetal) in the presence of acid catalyst to form a cyclic acetal orketal; and hydrogenating, or hydrogenating and further alkylating thecyclic acetal or ketal to give polyol ether derivatives represented byformulas (VII) to (X). Here, "alkylating" means a reaction that may alsobe referred to as "alkyl-capping." The reactions proceed as shown in thefollowing steps: ##STR14##

In the above formulas, R₁ represents a hydrogen atom, a linear alkylgroup having 1-21 carbon atoms or a branched alkyl group having 3-21carbon atoms. When R₁ is a hydrogen atom, R₂ is a linear alkyl grouphaving 1-21 carbon atoms or a branched alkyl group having 3-21 carbonatoms, preferably a linear alkyl group having 1-17 carbon atoms or abranched alkyl group having 3-17 carbon atoms, more preferably a linearalkyl group having 1-18 carbon atoms or a branched alkyl group having3-18 carbon atoms. When R₁ is a linear alkyl group having 1-21 carbonatoms or a branched alkyl group having 3-21 carbon atoms, R₂ is a linearalkyl group having 1-21 carbon atoms or a branched alkyl group having3-21 carbon atoms. It is preferable that both R₁ and R₂ independentlyare a linear alkyl group having 1-13 carbon atoms or a branched alkylgroup having 3-13 carbon atoms.

Examples of linear alkyl groups having 1-8 carbon atoms or a branchedalkyl groups having 3-8 carbon atoms represented by R₃ include methyl,ethyl, propyl, butyl, isobutyl, hexyl, and 2-ethylhexyl, with apreference given to methyl or ethyl.

R₄ represents a linear alkyl group having 1-6 carbon atoms or a branchedalkyl group having 3-6 carbon atoms. Y represents a residue of analkylating agent.

In brief, the polyol ether derivatives of the present invention areproduced by the following steps:

reacting a hexahydric alcohol such as sorbitol and mannitol representedby formula (V) with a carbonyl compound such as a ketone and an aldehyderepresented by formula (VI) for dehydration, or with a reactivederivative thereof represented by formula (2-VI') for dealcoholization,both in the presence of acid catalyst to give a cyclic acetal or ketalrepresented by formula (2-XIV); and

hydrogenating the cyclic acetal or ketal to give a polyol ether or apolyol ether acetal or ketal (here, "polyol ether acetal or ketal" meanspartially etherified and partially acetalized or ketalized polyol); or

further alkylating the polyol ether or the polyol ether acetal or ketalto give an alkylated (alkyl-capped) ether represented by formulas(2-XVI_(A)) and (2-XVI_(B)) after hydrogenation as mentioned above.

The starting materials used in the above-mentioned reactions will bedescribed in detail.

Hexahydric alcohol

Examples of hexahydric alcohols usable in the present invention arethose represented by formula (V), which include hexytols obtained byreducing hexoses, such as sorbitol, mannitol, galactitol, iditol,talitol, and allitol. From the view point of availability and cost,sorbitol is the most preferable.

Carbonyl compound

The carbonyl compounds usable in the present invention and representedby formula (VI) are ketones and aldehydes. Ketones are readily obtainedby high temperature decarboxylating dimerization of fatty acids,catalytic oxidation of olefins (Wacker process),oxidation-dehydrogenation of secondary alcohols, and oxidation ofcycloalkanes. Ketones obtained by Wacker process show a molecular weightdistribution, but they can be separated and purified by rectification.The ketones usable in the present invention are exemplified below, butnot limited to these examples.

Examples of methyl alkyl ketones include acetone, methyl ethyl ketone,methyl propyl ketone, methyl butyl ketone, methyl amyl ketone, methylhexyl ketone, methyl heptyl ketone, methyl octyl ketone, methyl nonylketone, methyl undecyl ketone, and methyl heptadecyl ketone.

Examples of dialkyl ketones include diethyl ketone, ethyl propyl ketone,ethyl butyl ketone, dipropyl ketone, ethyl pentyl ketone, ethyl hexylketone, dibutyl ketone, depentyl ketone, dihexyl ketone, diundecylketone, and diheptadecyl ketone.

Examples of polybranched ketones include methyl isopropyl ketone, methylsec-butyl ketone, methyl isobutyl ketone, ethyl isopropyl ketone, methyltert-butyl ketone, diisopropyl ketone, methyl isoamyl ketone, isopropylpropyl ketone, methyl neopentyl ketone, ethyl tert-butyl ketone,6-methyl-2-heptanone, 4-methyl-3-heptanone, 2-methyl-3-heptanone,5-methyl-3-heptanone, diisobutyl ketone, and 6,10-dimethyl-2-undecanone.

Examples of cyclic ketones include cyclopropanone, cyclobutanone,cyclopentanone, cyclohexanone, 2-methyl cyclopentanone,3-methylcyclopentanone, 2-methylcyclohexanone, 3-methylcyclohexanone,4-methylcyclohexanone, cycloheptanone, 2,4-dimethylcyclohexanone,2,6-dimethylcyclohexanone, 3,3,5-trimethylcyclohexanone,2-tert-butylcyclohexanone, 4-tert-butylcyclohexanone,2-isopropyl-4-methylcyclohexanone, and cyclodecanone.

Examples of cyclic alkyl ketones include methyl cyclohexyl ketone, and5-(2',2',5'-trimethylcyclohexyl)-2-pentanone.

Aldehydes used in the present invention are those readily prepared bythe following methods: dehydrogenation of fatty alcohols,hydroformylation of olefins (oxo method), Rosenmund reduction of fattyacid chlorides, and direct hydrogenation of fatty acids. In the case ofthe oxo method, both linear and branched aldehydes are produced, butthey can be separated and purified by rectification.

The aldehydes mentioned below are just examples usable in the presentinvention and are not limitative.

Examples of linear alkyl aldehydes include acetaldehyde,propionaldehyde, butyraldehyde, valeraldehyde, caproaldehyde, heptanal,octanal, decanal, dodecanal, tetradecanal, octadecanal, andbehenaldehyde.

Examples of α-branched alkyl aldehydes include isobutyraldehyde,2-methylbutyraldehyde, 2-methylpentanal, 2-ethylbutanal,2-methylhexanal, 2-ethylpentanal, 2-methylheptanal, 2-ethylhexanal, and2-propylpentanal.

Examples of α- and other polybranched alkyl aldehydes having one or morebranches at positions other than α-position include 2,3-dimethylbutanal,2,4,4-trimethylpentanal, and 2-isopropyl-5-methylhexanal.

Other examples of other branched alkyl aldehydes having one or morebranches at positions other than α-position include isovaleraldehyde,3-methylpentanal, 4-methylpentanal, 3,3-dimethylbutanal,3-methylhexanal, 4-methylhexanal, 5-methylhexanal,3,5,5-trimethylhexanal, isodecylaldehyde, 3,7-dimethyloctanal, andisooctadecanal.

Examples of cyclic alkyl aldehydes include cyclopentylacetaldehyde, andcyclohexylacetaldehyde.

Reactive derivatives of carbonyl compounds

Reactive derivatives of carbonyl compounds used in the present inventionare ketals and acetals represented by formula (2-VI') which can readilybe obtained by the reaction of a ketone or aldehyde as mentioned abovewith a lower alcohol having 1-6 carbon atoms in the presence of an acidcatalyst. Examples of lower alcohols having 1-6 carbon atoms which giveR₄ residue include methanol, ethanol, propanol, isopropanol, butanol,isobutanol, sec-butanol, tert-butanol, amyl alcohol, isoamyl alcohol,neopentyl alcohol, 1-methylbutanol, 1,1-dimethylpropanol,1-ethylpropanol, hexanol, isohexanol, 2-ethylbutanol, 1-methylamylalcohol, 1,3-dimethylbutanol, and 1-ethylbutanol.

Ketalization

In the present invention, the reaction between a hexahydric alcoholrepresented by formula (V) and a ketone is ketalization. The molar ratioof the ketone to the hexahydric alcohol is in the range of from 1 to 15,preferably from 1.5 to 7.5. This reaction requires an acidic catalyst,such as p-toluenesulfonic acid, methanesulfonic acid, and sulfuric acidin an amount of 0.05 to 10 mole %, preferably 0.1 to 7 mole %, and morepreferably 0.5 to 5 mole % to the amount of the hexahydric alcoholrepresented by formula (V).

The above reaction may be carried out with or without solvents. Solventsusable in the present invention include inert solvents, such as xylene,toluene, benzene, octane, isooctane, heptane, hexane, cyclohexane,pentane, ligroin, and petroleum ether. These solvents are used singly orin combination. The reaction temperature depends upon the boiling pointof the ketone used, and the reaction is normally carried out at atemperature of from 40° to 160° C., preferably from 60° to 100° C.,while removing the water formed in the process of the reaction. Thereare also some cases where the reaction can effectively be carried outunder a reduced pressure. In the above temperature range, the reactioncan favorably proceed and coloration due to side reactions is lesslikely to occur. Also, the reaction may be carried out in a nitrogenstream, nitrogen atmosphere, or dry air. The reaction time varies withreaction conditions employed, but it is generally preferred to continuethe reaction for 5 to 200 hours. The cyclic ketals obtained (2-XIV) areneutralized and subjected to pretreatments, such as filtration andwashing. Then, the ketals can be purified by such means as adsorption,crystallization, and distillation.

Acetalization

In the present invention, the reaction between a hexahydric alcoholrepresented by formula (V) and an aldehyde is acetalization. The molarratio of the aldehyde to the hexahydric alcohol is in the range of from1 to 6, preferably from 1.5 to 3.8. This reaction requires an acidiccatalyst, such as p-toluenesulfonic acid, methanesulfonic acid, andsulfuric acid, in an amount of 0.01 to 5 mole %, preferably 0.05 to 3mole %, and more preferably 0.1 to 2 mole % to the amount of thehexahydric alcohol represented by formula (V).

The above reaction may be carried out with or without solvents. Solventsusable in the present invention include inert solvents, such as xylene,toluene, benzene, octane, isooctane, heptane, hexane, cyclohexane,pentane, ligroin, and petroleum ether. These solvents are used singly orin combination. The reaction temperature depends upon the boiling pointof the aldehyde used, and the reaction is normally carried out at atemperature of from 20° to 130° C., preferably from 40° to 100° C.,while removing the water in the process of the reaction. There are alsosome cases where the reaction can effectively proceed under a reducedpressure. In the above temperature range, the reaction can favorablyproceed and coloration due to side reactions is less likely to occur.Also, the reaction may be carried out in a nitrogen stream, nitrogenatmosphere, or dry air. The reaction time varies with reactionconditions employed, but it is generally preferred to continue thereaction for 1 to 30 hours. The cyclic acetals obtained (2-XIV) areneutralized and subjected to pretreatments, such as filtration andwashing. Then, the acetals can be purified by conventional means, suchas adsorption, crystallization, and distillation.

Transketalization

In the present invention, the reaction between a hexahydric alcoholrepresented by formula (V) and a ketal (2-VI'), a reactive derivative ofketone, is transketalization. The molar ratio of the ketal to thehexahydric alcohol is in the range of from 1 to 15, preferably from 1.5to 7.5. This reaction requires an acidic catalyst, such asp-toluenesulfonic acid, methanesulfonic acid, and sulfuric acid, in anamount of 0.05 to 10 mole %, preferably 0.1 to 7 mole %, and morepreferably 0.5 to 5 mole % to the amount of the hexahydric alcoholrepresented by formula (V).

The above reaction may be carried out with or without solvents. Solventsusable in the present invention include inert solvents, such as xylene,toluene, benzene, octane, isooctane, heptane, hexane, cyclohexane,pentane, ligroin, and petroleum ether. These solvents are used singly orin combination. Though the reaction temperature depends upon the boilingpoints of the ketal (2-VI') used and the lower alcohol formed, thereaction is carried out at a temperature of from 40° to 160° C.,preferably from 60° to 130° C., while removing the lower alcohol formedin the process of the reaction. There are also some cases where thereaction can effectively be carried out under a reduced pressure. In theabove temperature range, the reaction can favorably proceed andcoloration due to side reactions is less likely to occur. Also, thereaction may be carried out in a nitrogen stream, nitrogen atmosphere,or dry air. The reaction time varies with reaction conditions employed,but it is generally preferred to continue the reaction for 5 to 200hours. The cyclic ketals obtained (2-XIV) are neutralized and subjectedto pretreatments, such as filtration and washing. Then, the cyclicketals can be purified by conventional means, such as adsorption,crystallization, and distillation.

Transacetalization

In the present invention, the reaction between a hexahydric alcoholrepresented by formula (V) and an acetal (2-VI'), a reactive derivativeof aldehyde, is transacetalization. The molar ratio of the acetal(2-VI') to the hexahydric alcohol is in the range of from 1.5 to 6,preferably from 2.7 to 3.8. This reaction requires an acidic catalyst,such as p-toluenesulfonic acid, methanesulfonic acid, and sulfuric acid,in an amount of 0.01 to 5 mole %, preferably 0.05 to 3 mole %, and morepreferably 0.1 to 2 mole % to the amount of the hexahydric alcoholrepresented by formula (V).

The above reaction may be carried out with or without solvents. Solventsusable in the present invention include inert solvents, such as xylene,toluene, benzene, octane, isooctane, heptane, hexane, cyclohexane,pentane, ligroin, and petroleum ether. These solvents are used singly orin combination. The reaction temperature depends upon the boiling pointsof the acetal used and the lower alcohol formed, and the reaction isnormally carried out at a temperature of from 20° to 150° C., preferablyfrom 40° to 130° C., while removing the lower alcohol formed in theprocess of the reaction. There are also some cases where the reactioncan effectively proceed under a reduced pressure. In the abovetemperature range, the reaction can favorably proceed and coloration dueto side reactions is less likely to occur. Also, the reaction may becarried out in a nitrogen stream, nitrogen atmosphere, or dry air. Thereaction time varies with reaction conditions employed, but it isgenerally preferred to continue the reaction for 1 to 30 hours. Thecyclic acetals obtained (2-XIV) are neutralized and subjected topretreatments, such as filtration and washing. Then, the acetals can bepurified by conventional means, such as adsorption, crystallization, anddistillation.

Hydrogenation

The hydrogenation of the cyclic ketal or cyclic acetal represented byformula (2-XIV) can be carried out using a conventional hydrogenolysiscatalyst, such as palladium, rhodium, ruthenium, and platinum, in anamount of from 5 to 5000 ppm to the amount of cyclic acetal or cyclicketal, under normal to 250 kg/cm² of hydrogen pressure, at a temperatureof from 50° to 250° C., for 1 to 30 hours. The above hydrogenolysiscatalysts may be carried on the surface of carriers, such as carbon,alumina, silica, diatomaceous earth, and titanium oxide, at a ratio of0.1 to 20%. As for hydrogenolysis catalyst, palladium, especially havinga pH of 5 to 8, is particularly preferable. It is also preferred toremove moisture from the catalyst before use. This reaction may becarried out with or without solvents. When a solvent is used, thefollowing inert solvents can be used singly or in combination: decane,octane, isooctane, heptane, hexane, and cyclohexane. The startingmaterials of cyclic acetals or ketals, such as hexahydric alcoholsrepresented by formula (V), aldehydes, and ketones, may be added to thereaction system. Acidic substances, such as phosphoric acid, may beadded in a slight amount. The reaction may be carried out in a closedsystem or under a hydrogen stream.

In this hydrogenation reaction, the bond between carbon and oxygen atomsin an acetal or ketal is reductively cleaved to give an ether andalcohol, and intermolecular transformation of acetals or ketals occursat the same time. Accordingly, the starting materials of triacetal ortriketal generally can yield a mixture of alkyl ethers with differentnumbers of substituents ranging from 1 to 5. In the resulting alkylethers having the same number of substituents, those etherified at 1and/or 6 positions are predominant. When the reaction is discontinued onthe way, ether alcohols having acetal or ketal rings can be obtained.When alkyl ethers having a smaller number of alkyl or alkylidenesubstituents are to be obtained, acetals or ketals which are prepared byusing an aldehyde or a ketone or a reactive derivative thereof in anamount smaller than the equivalent of a hexahydric alcohol may besubjected to the hydrogenation. Alkyl ethers with a smaller number ofsubstituents can also be obtained by adding a hexahydric alcohol to atriacetal or a triketal, and carrying out the hydrogenation reaction.

When alkyl ethers having a smaller number of alkyl substituents and noacetal or ketal rings are to be obtained, hydrogenation may bediscontinued on the way and hydrolysis is carried out in a methanol orethanol aqueous solution using p-toluensulfonic acid, sulfuric acid, orhydrochloric acid as a catalyst.

When alkyl ethers having a larger number of alkyl substituents are to beobtained in a larger quantity, an acetal or ketal is further added tothe hydrogenation reaction system.

The thus-obtained mixture of polyol ethers (2-XV_(A)), the mixture ofpolyol ether acetals (2-XV_(B)), or the mixture of polyol ether ketals(2-XV_(B)), each mixture containing hydrogenation products withdifferent numbers of alkyl substituents, may be subjected to thesubsequent alkylation directly, or, if necessary, after a desired polyolether or the like is isolated.

The isolation of a desired polyol ether or the like from the reactionmixtures can be carried out by conventional means after removing thecatalyst used by filtration. For example, evaporation of solvent,washing, recrystallization, distillation, and chromatography may beemployed solely or in combination.

Alkylation (alkyl-capping)

Ether compounds represented by formulas (2-XVI_(A)) and (2-XVI_(B)) areobtained by treating the hydroxyl groups of the polyol ethers (2-XV_(A))or polyol ether ketals or acetals (2-XV_(B)) obtained by theabove-mentioned process with a base, such as Na, NaH, NaOCH₃, NaOH, andKOH, to give a corresponding alcoholate, and treating the alcoholatewith an alkylating agent, such as an alkyl halide, dialkyl sulfate, andalkyl tosylate, to alkylate the hydroxyls of the polyol ethers or polyolether ketals or acetals.

The alkyl halides used in the above reaction include the followinghalogenated lower alkyls: chlorides of linear alkyls, such as methylchloride, ethyl chloride, propyl chloride, butyl chloride, amylchloride, hexyl chloride, and octyl chloride; chlorides of branchedalkyls such as isopropyl chloride, isobutyl chloride, sec-butylchloride, isoamyl chloride, neopentyl chloride, 1-methylbutyl chloride,1-ethylpropyl chloride, isohexyl chloride, 2-ethylbutyl chloride,1-methylamyl chloride, 1-ethylbutyl chloride, and 2-ethylhexyl chloride;bromides of linear alkyls, such as methyl bromide, ethyl bromide, propylbromide, butyl bromide, amyl bromide, and hexyl bromide; bromides ofbranched alkyls, such as isopropyl bromide, isobutyl bromide, sec-butylbromide, isoamyl bromide, neopentyl bromide, 1-methylbutyl bromide,1-ethylpropyl bromide, isohexyl bromide, 2-ethylbutyl bromide,1-methylamyl bromide, 1-ethylbutyl bromide, and 2-ethylhexyl bromide;iodides of linear alkyls, such as methyl iodide, ethyl iodide, propyliodide, butyl iodide, amyl iodide, and hexyl iodide; iodides of branchedalkyls, such as isopropyl iodide, isobutyl iodide, sec-butyl iodide,isoamyl iodide, neopentyl iodide, 1-methylbutyl iodide, 1-ethylpropyliodide, isohexyl iodide, 2-ethylbutyl iodide, 1-methylamyl iodide,1,3-dimethylbutyl iodide, and 1-ethylbutyl iodide. In view ofreactivity, a preference is given to primary alkyl halides. It is alsopreferred that these alkyl halides have a boiling point of not higherthan 50° C. so that chlorine, bromine or iodine will not remain afterthe reaction.

Examples of dialkyl sulfates are the following lower dialkyl sulfates:linear dialkyl sulfates, such as dimethyl sulfate, diethyl sulfate,dipropyl sulfate, dibutyl sulfate, diamyl sulfate, and dihexyl sulfate;and branched dialkyl sulfates, such as diisopropyl sulfate, diisobutylsulfate, di-sec-butyl sulfate, diisoamyl sulfate, dineopentyl sulfate,di(1-methylbutyl)sulfate, di(1-ethylpropyl)sulfate, diisohexyl sulfate,di(2-ethylbutyl)sulfate, di(1-methylamyl)sulfate, anddi(1-ethylbutyl)sulfate. In view of reactivity, a preference is given toprimary alkyl sulfates.

Examples of alkyl tosylates are the following lower alkyl tosylates:linear alkyl tosylates, such as methyl tosylate, ethyl tosylate, propyltosylate, butyl tosylate, amyl tosylate, and hexyl tosylate; andbranched alkyl tosylates, such as isopropyl tosylate, isobutyl tosylate,sec-butyl tosylate, isoamyl tosylate, neopentyl tosylate, 1-methylbutyltosylate, 1-ethylpropyl tosylate, isohexyl tosylate, 2-ethylbutyltosylate, 1-methylamyl tosylate, 1,3-dimethyl tosylate, and 1-ethylbutyltosylate. In view of reactivity, a preference is given to primary alkyltosylates.

In the alkylation process, the molar ratio of a base to a hydroxyl groupof polyol ethers (2-XV_(A)) or polyol ether ketals or acetals (2-XV_(B))is 1.0 to 3.0, preferably 1.0 to 1.5; and the molar ratio of analkylating agent to the hydroxyl group is 1.0 to 3.0, preferably 1.0 to1.5. The alcoholate forming reaction is carried out in an inert solventor in a mixture of solvents, the solvents including xylene, toluene,benzene, octane, isooctane, heptane, hexane, cyclohexane, pentane,ligroin, petroleum ether, dimethyl sulfoxide, and 1,2-dimethoxydiethane,at a temperature in the range of from room temperature to 110° C., thetemperature depending on the boiling point and stability of the solventsused. Then, O-alkylation is carried out by adding an alkylating agentdropwise at a temperature of from room temperature to 130° C., thetemperature depending on the reactivity of the alkylating agent. Thealcoholate forming reaction is continued for 0.5 to 2 hours. Thereaction time for O-alkylation depends on the degree of exotherm, and itis continued preferably for 0.5 to 6 hours as long as the exothermicreaction can be kept under control. After the completion of thereaction, alcoholates and the alkylating agents which remain unchangedare decomposed by adding an aqueous solution of an alkali, such assodium hydroxide. After the resulting ether compounds represented byformulas (2-XVI_(A)) and (2-XVI_(B)) are subjected to pretreatments,such as extraction, filtration, and washing, and they are purified bysuch a means as adsorption, steaming, dehydration, and distillation.

(3) A working fluid composition for a refrigerating machine comprising arefrigeration oil containing polyol ether derivatives as a base oil anda hydrofluorocarbon

The working fluid composition for a refrigerating machine of the presentinvention is characterized by comprising polyol ether derivativesrepresented by formula (XI) as a base oil of a refrigeration oil.

In formula (XI), R¹ to R⁶ may be identical or different, eachrepresenting a linear alkyl group having 1-14 carbon atoms, a branchedalkyl group having 3-14 carbon atoms or a cyclic alkyl group having 3-14carbon atoms. The total number of carbon atoms of R¹ to R⁶ is in therange of from 8 to 40.

Generally, the compatibility of a compound used as a base oil with ahydrofluorocarbon becomes better as the polarity increases, whereas theinsulating property becomes better as the polarity decreases. Therefore,it is important to appropriately balance the polarity of a compound usedas a base oil of a refrigeration oil.

In the case of an alkyl ether having an alcohol residue with a smallnumber of hydroxyls, e.g., 3 to 4 hydroxyls, it is required for thealkyl group of the ether to have a larger number of carbon atoms to getan appropriate viscosity. This makes the polarity of the alkyl etherlower, and thereby makes the compatibility with a hydrofluorocarbonpoor. On the other hand, in the case of an alkyl ether having an alcoholresidue with a large number of hydroxyls, e.g., 12 to 13 hydroxyls, itis required for the alkyl group of the ether to have a smaller number ofcarbon atoms to get an appropriate viscosity. This makes the polarity ofthe alkyl ether higher and thereby makes the insulating property poor.Therefore, an alcohol residue having 6 hydroxyls is particularlypreferable for appropriately balancing the above factors.

The hexahydric alcohols, which give the hexahydric alcohol residue (thestructure which remains after deleting R¹ O-- to R⁶ O-- from formula(XI)), include the hexahydric alcohols exemplified as the startingmaterials set forth in "(2) A novel method for producing polyol etherderivatives." Among the examples, sorbitol is the most preferable interms of availability and cost.

The linear alkyl group having 1-14 carbon atoms, the branched alkylgroup having 3-14 carbon atoms or the cyclic alkyl group having 3-14carbon atoms represented by R¹ to R⁶ in formula (XI) are those asexemplified below.

Among the examples of linear alkyl groups having 1-21 carbon atoms orbranched alkyl groups having 3-21 carbon atoms represented by R₁ setforth in "(1) Novel polyol ether derivatives," those having 1-14 carbonatoms can be examples of the alkyls represented by R¹ to R⁶ in formula(XI). Also, alkyls having a tertiary and no hydrogen atom at α-positioncan be exemplified by 1,1-dimethylethyl, 1-methylcyclopropyl,1,1-dimethylpropyl, 1-methylcyclobutyl, 1,1-dimethylbutyl,1,1,2-trimethylpropyl, 1-methylcyclopentyl, 1,1-dimethylpentyl,1-methyl-1-ethylbutyl, 1,1-diethylpropyl, and 1,1-diethylbutyl.

Examples of α-cyclic alkyl groups include cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, 2-methylcyclopentyl,3-methylcyclopentyl, 2-methylcyclohexyl, 3-methylcyclohexyl,4-methylcyclohexyl, 2,4-dimethylcyclohexyl, 2,6-dimethylcyclohexyl,3,3,5-trimethylcyclohexyl, 2-tert-butylcyclohexyl,4-tert-butylcyclohexyl, 2-isopropyl-4-methylcyclohexyl, and cyclodecyl.

Examples of cycloalkyl groups include cyclopentylmethyl,cyclohexylmethyl, 1-methyl-4-(2'2'5'-trimethylcyclohexyl)butyl, and1-cyclohexylethyl.

Examples of alkyl groups having tert-carbons and no hydrogen atoms atboth α- and β-positions include 1,1,2,2-tetramethylpropyl,1,1,2,2-tetramethylbutyl, and 1,1,2,2-tetramethylhexyl.

For satisfactory compatibility with hydrofluorocarbons and insulatingproperty, the ratio of the total number of carbon atoms to the totalnumber of oxygen atoms in a molecule (C/O) is preferably in the range offrom 2.5 to 7.5, more preferably 3.0 to 7.0, even more preferably 3.0 to7.0, and particularly preferably 4.0 to 6.0.

Accordingly, the total number of carbon atoms is normally in the rangeof 8 to 40, preferably 9 to 39, more preferably 12 to 36, and still morepreferably 18 to 30. When the total number of carbon atoms is less than8, it results in poor insulating property; when it is higher than 40,compatibility with hydrofluorocarbons becomes poor.

In order to get better compatibility with hydrofluorocarbons, branchedand cyclic alkyls are preferred to linear alkyls. Between branched andcyclic alkyls, a preference is given to branched alkyls. Alkenyls andalkinyls having unsaturated bonds are not preferable because of poorthermal stability.

The names and structures of the polyol ether derivatives represented byformula (XI) are listed below. However, they are not limitative, andcompounds represented by formulas (XIII_(AA)) and (XIII_(BB)) are alsoincluded in the polyol ether derivatives of the present invention.##STR15##

The above polyol ether derivatives represented by formula (XI) can beproduced by various methods, For example, it can be produced by thereaction of a hexitol alcoholate, a reactive derivative of hexitol, withan alkyl halide. However, halogen, such as chlorine, bromine or iodine,undesirably remains in the product obtained by this method, whichimpairs thermal stability of the product.

Therefore, the method described above in "(2) Novel method for producingpolyol ether derivatives" is recommended as an economical and simplemethod because it does not use compounds having halogen, such aschlorine, bromine, or iodine.

Specifically, the polyol ether derivatives represented by formula (XI)is synthesized by the steps of reacting a hexahydric alcohol representedby formula (V) with one or more carbonyl compounds (ketone or aldehyde)represented by formula (XII) for ketalization or acetalization, or withreactive derivatives of the carbonyl compounds (ketal or acetal) fortransketalization or transacetalization to obtain cyclic ketals orcyclic acetals; hydrogenating the cyclic ketals or the cyclic acetals toobtain polyol ethers; and alkylating the polyol ethers to give polyolether derivatives.

In formula (XII), R⁷ represents a hydrogen atom, a linear alkyl grouphaving 1-13 carbon atoms, a branched alkyl group having 3-13 carbonatoms or a cyclic alkyl group having 3-13 carbon atoms, and R⁸represents a linear alkyl group having 1-13 carbon atoms, a branchedalkyl group having 3-13 carbon atoms or a cyclic alkyl group having 3-13carbon atoms with the proviso that R⁷ and/or R⁸ have at least onehydrogen atom at α-position to the carbonyl group and the total numberof carbon atoms of R⁷ and R⁸ is 1-13; and R⁷ and R⁸ may together join toform a ring with an alkylene group having 2-13 carbon atoms.

The following is an example scheme of the above reaction. ##STR16##

This reaction mainly produces, as a polyol ether (3-XVIII), two-molaradducts (3-XVIII_(A)), three-molar adducts (3-XVIII_(B)), and four-molaradducts (3-XVIII_(C)), with small quantities of one-molar adducts(3-XVIII_(D)) and five-molar adducts (3-XVIII_(E)). ##STR17##

In the above formulas, R¹ to R⁶ have the same meanings as those informula (XI). However, in the above-mentioned reaction scheme, R¹ to R⁶correspond to the residues of the carbonyl compound represented byformula (XII) or the residues of the reactive derivative thereof, and,therefore, can be represented by the following formula:

    alkyl group: --CHR.sup.7 R.sup.8.

The polyol ethers (3-XVIII) can be separated to the compounds(3-XVIII_(A)) to (3-XVIII_(E)) by conventional methods for purification,such as distillation, chromatography, or liquid-liquid extraction. Eachof the polyol ethers (3-XVIII_(A)) to (3-XVIII_(E)) may be separatelysubjected to alkylation, or the mixture of the polyol ethers may bealkylated without separation.

Examples of usable hexahydric alcohols represented by formula (V) arehexitols obtained by reducing hexoses as mentioned above in "(2) A novelmethod for producing polyol ether derivatives," the hexitol includingsorbitol, mannitol, galactitol, iditol, talitol, and allitol.

Usable carbonyl compounds represented by formula (XII) are carbonylcompounds having 2-14 carbon atoms including the carbonyl carbon atom,examples of which are set forth in "(2) A novel method for producingpolyol ether derivatives."

The method for producing the polyol ether derivatives as mentioned abovein "(2) Novel method for producing polyol ether derivatives" can beemployed.

In the hydrogenation reaction, intermediate substances, such as polyolether ketals and polyol ether acetals, are produced. Examples of suchintermediate compounds are represented by the following formulas(3-XIX_(A)) to (3-XIX_(C)), the compounds having one or more ether bondsas well as one or more ketal or acetal rings in a molecule. ##STR18##

When the polyol ethers (3-XVIII) are obtained as a mixture containingthe polyol ether ketals or polyol ether acetals (3-XIX_(A) to3-XIX_(C)), the polyol ethers containing no ketal or acetal rings(3XVIII) can be obtained by hydrolysis. Specifically, the mixtureobtained is filtered, and volatile materials in the filtrate areevaporated. The residue is then subjected to hydrolysis in a mixedacidic solution consisting of an adequate amount of acid catalyst, suchas 0.1 to 1N hydrochloric acid and ethanol.

Also, the mixture of the polyol ethers (3-XVIII) containing those havingketal or acetal rings may be directly subjected to the subsequentalkylation. The polyol ether ketals or polyol ether acetals (3-XIX_(A)to 3-XIX_(C)) are alkylated to form the ether compounds as representedby formulas (XIII_(AA)) and (XIII_(BB)).

In formulas (XIII_(AA)) and (XIII_(BB)), R¹ to R⁶ may be identical ordifferent, each representing a linear alkyl group having 1-14 carbonatoms, a branched alkyl group having 3-14 carbon atoms or a cyclic alkylgroup having 3-14 carbon atoms; R⁷ represents an hydrogen atom, or alinear alkyl group having 1-13 carbon atoms, a branched alkyl grouphaving 3-13 carbon atoms or a cyclic alkyl group having 3-13 carbonatoms; R⁸ represents a linear alkyl group having 1-13 carbon atoms, abranched alkyl group having 3-13 carbon atoms or a cyclic alkyl grouphaving 3-13 carbon atoms; R⁷ and R⁸ may together join to form a ringwith an alkylene group having 2-13 carbon atoms; the total number ofcarbon atoms is 8-40 for R¹, R², R³, R⁶, R⁷ and R⁸ in formula(XIII_(AA)), and for R¹, R⁴, R⁵, R₆, R⁷ and R⁸ in formula (XIII_(BB)),and is 1-13 for R⁷ and R⁸ for both formulas; and "a" to "e" are symbolsfor structure unit, and "a"-"c" or "d"-"e" may be arranged in anysequential order.

The above ether compounds, when used as a base oil for a working fluidcomposition for a refrigerating machine, give the same effect as thepolyol ether derivatives represented by formula (XI), and, therefore,these compounds can be used similarly in a working fluid composition fora refrigerating machine. In such a case, the polyol ether derivativesrepresented by formula (XIII_(AA)) or (XIII_(BB)) may be used alone oras a mixture with the polyol ether derivatives represented by formula(XI). When the polyol ether derivatives represented by formula(XIII_(AA)) or (XIII_(BB)) are used alone, polyol ether acetals orpolyol ether ketals separated from a mixture of polyol ethers may bealkylated, or the polyol ether derivatives represented by formula(XIII_(AA)) or (XIII_(BB)) may be separated from the polyol etherderivatives obtained after alkylation. The methods for separation andalkylation are the same as those for the polyol ether derivativesrepresented by formula (XI).

The alkyl, alcohol residue, and other groups of the polyol etherderivatives represented by formulas (XIII_(AA)) and (XIII_(BB)) are thesame as those represented by formula (XI).

The thus-obtained polyol ether derivatives represented by formulas (XI)and (XIII_(AA)) or (XIII_(BB)) may be used after purification to removeby-products or unchanged compounds, or may be used without purificationas long as the presence of a small amount of by-products and unchangedcompounds does not impair the effects of the present invention. Forexample, a portion of ketals or acetals (3-XVII) may remainunhydrogenated, and un-capped hydroxyls may also remain.

The polyol ether derivatives represented by formulas (XI) and(XIII_(AA)) or (XIII_(BB)) and used in the working fluid composition fora refrigerating machine described above in "(3) A working fluidcomposition for a refrigerating machine comprising a refrigeration oilcontaining as a base oil polyol ether derivatives and ahydrofluorocarbon" are hereinafter simply referred to as the ethercompounds in the present invention) are not particularly restricted inmolecular weight. However, when they are used as a refrigeration oil,the average molecular weight is preferably in the range of from 200 to800, more preferably 300 to 700 in view of better sealing for thecompressor, compatibility with hydrofluorocarbon, and lubricity.

The viscosity of the ether compounds in the present invention at 100° C.is preferably 0.5 to 30 mm² /s, more preferably 1 to 15 mm² /s. When theviscosity of the ether compounds in the present invention at 100° C.exceeds 30 mm² /s, the compatibility with hydrofluorocarbons becomespoor. The viscosity at 40° C. of the ether compounds in the presentinvention is preferably 1 to 300 mm² /s, more preferably 5 to 100 mm²/s. Among the ether compounds in the present invention having aviscosity in the above ranges, preferable are those of which phaseseparation temperature at low temperature is low. Specifically, suitableexamples are those having a critical solution temperature of not higherthan 10° C., more preferably not higher than 0° C., further preferablynot higher than -10° C.

When used as a refrigeration oil for room air conditioners andrefrigerators, the ether compounds in the present invention are requiredto have good insulating properties. Specifically, the volume resistivityof the ether compounds in the present invention is normally not lessthan 10¹¹ Ω·cm, preferably not less than 10¹² Ω·cm, more preferably notless than 10¹³ Ω·cm. In order to prevent the solidification of therefrigeration oil at low temperatures, the pour point of the ethercompounds in the present invention is preferably not higher than -10°C., more preferably not higher than -20° C.

The refrigeration oil containing the ether compounds in the presentinvention as a base oil may be a mixture of the ether compounds in thepresent invention with other synthetic oils, such as mineral oils, polya-olefins, alkyl benzenes, other ethers and polyethers, PAG, PAG-OH,ketones, esters, perfluoropolyethers, and phosphates. Theabove-mentioned ether compounds may be used singly or as a mixture oftwo or more kinds for refrigeration oil containing as a base oil theether compounds in the present invention.

The ether compounds in the present invention may be used with or withoutvarious additives.

For example, room air conditioners are commonly filled with arefrigerant upon installation, and, therefore, there is a high risk ofwater contamination. Although the ether compounds in the presentinvention are chemically stable in the presence of water, the insulatingmaterials, such as PET film, may be hydrolyzed in the presence of waterto yield PET oligomers, which may result in plugged capillaries ofrefrigerating machines. Therefore, it is preferred to use additives forremoving water, such as epoxy compounds having an epoxy group,orthoesters, acetals (ketals), and carbodiimides.

The refrigeration oil comprising the ether compounds in the presentinvention which further comprises one or more compounds selected fromthe group consisting of (a) compounds having an epoxyl group, (b)orthoesters, (c) acetals (ketals), and (d) carbodiimides allows toprovide a further improved refrigeration oil, and is an extremelypreferable embodiment of the refrigeration oil using as a base oil theether compounds in the present invention. Accordingly, a working fluidcomposition for a refrigerating machine comprising such an improvedrefrigeration oil and a hydrofluorocarbon is an extremely preferableembodiment of the working fluid composition for a refrigerating machineof the present invention.

(a) Compounds having epoxy groups are those having 4-60 carbon atoms,preferably those having 5-25 carbon atoms. Suitable examples includeglycidyl ethers, such as phenylglycidyl ether, butylglycidyl ether,2-ethylhexylglycidyl ether, cresylglycidyl ether,neopentylglycoldiglycidyl ether, 1,6-hexanediol diglycidyl ether,glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, andpentaerythritol tetraglycidyl ether; glycidyl esters, such as diglycidylphthalate, diglycidyl cyclohexanedicarboxylate, diglycidyl adipate, andglycidyl 2-ethylhexanoate; epoxidated monoesters of fatty acids, such asmethyl epoxystearate, and butyl epoxystearate; epoxidated vegetableoils, such as epoxidated soybean oil and epoxidated linseed oil; andalicyclic epoxy compounds, such as epoxycyclooctane, epoxycycloheptaneand compounds having an epoxycyclohexyl group and compounds having anepoxycyclopentyl group exemplified below.

The compounds having an epoxycyclohexyl or an epoxycyclopentyl are thosehaving 5 to 40 carbon atoms, preferably 5-25 carbon atoms. Specifically,those set forth in column 11, lines 34 to 46 of Japanese PatentLaid-open No. 5-209171 are suitably used. Though they are notparticularly limited, a preference is given to 1,2-epoxycyclohexane,1,2-epoxycyclopentane, bis(3,4-epoxycyclohexylmethyl)adipate,bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate,3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and2-(7-oxabicyclo 4.1.0!hept-3-yl)-spiro(1,3-dioxane-5,3'- 7!oxabicyclo4.1.0!heptane).

In the present invention, the above epoxy compounds may be used singlyor in combination of two or more kinds. The amount of the epoxy compoundto be added is usually 0.05 to 2.0 parts by weight, preferably 0.1 to1.5 parts by weight, more preferably 0.1 to 1.0 parts by weight, basedon 100 parts by weight of the ether compounds in the present inventionused.

(b) The orthoesters used in the present invention are those having 4-70carbon atoms, preferably those having 4-50 carbon atoms. Specifically,orthoesters set forth in column 10, lines 7-41 of Japanese PatentLaid-Open No. 6-17073 are suitably used. The amount of orthoesters to beadded is normally 0.01 to 100 parts by weight, preferably 0.05 to 30parts by weight, based upon 100 parts by weight of the ether compoundsin the present invention used.

(c) The acetals or ketals added in the present invention are thosehaving 4-70 carbon atoms, preferably those having 4-50 carbon atoms.Specifically, those set forth in column 10, line 47 to column 11, line21 of Japanese Patent Laid-Open No. 6-17073 are suitably used. Theamount of acetals or ketals to be added is normally 0.01 to 100 parts byweight, preferably 0.05 to 30 parts by weight, based upon 100 parts byweight of the ether compounds in the present invention used.

(d) Carbodiimides used in the present invention is represented by thefollowing formula:

    R.sub.10 --N═C═N--R.sub.11

wherein R₁₀ and R₁₁ represent a hydrocarbon group having 1-20 carbonatoms, preferably 1-12 carbon atoms; and R₁₀ and R₁₁ may be identical ordifferent.

Examples of R₁₀ and R₁₁ include alkyl groups, such as methyl, ethyl,propyl, isopropyl, cyclopropyl, butyl, 1-methylpropyl, 2-methylpropyl,t-butyl, pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl,1-ethylpropyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl,2,2-dimethylpropyl, cyclopentyl, hexyl, 1-methylpentyl, 2-methylpentyl,3-methylpentyl, 4-methylpentyl, 1-ethylbutyl, 2-ethylbutyl,1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl,2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl,1-ethyl-2-methylpropyl, 1-ethyl-1-methylpropyl, 1,1,2-trimethylpropyl,1,2,2-trimethylpropyl, cyclohexyl, cyclopentylmethyl, methylcyclopentyl,heptyl, 1-methylhexyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl,5-methylhexyl, 1-ethylpentyl, 2-ethylpentyl, 2,4-dimethylpentyl,3,4-dimethylpentyl, 1,1-dimethylpentyl, 1,4-dimethylpentyl,1-propylbutyl, 1-isopropylbutyl, 1,3,3-trimethylbutyl,1,1-diethylpropyl, 2,2-dimethyl-1-ethylpropyl,1,2-dimethyl-1-ethylpropyl, 1-isopropyl-2-methylpropyl, cycloheptyl,cyclohexylmethyl, methylcyclohexyl, octyl, 1-methylheptyl,2-methylheptyl, 1-ethylhexyl, 2-ethylhexyl, 1,1,3,3-tetramethylbutyl,1,1-diisopropylethyl, 1-ethyl-1,2,2-trimethylpropyl, 1,5-dimethylhexyl,3,5-dimethylhexyl, 2-propylpentyl, 2,4,4-trimethylpentyl,1-ethyl-2-methylpentyl, 2,2-dimethylhexyl, 1,1-dimethylhexyl,cycloheptylmethyl, dimethylcyclohexyl, 4-methylcyclohexylmethyl,cycloheptylmethyl, cyclooctyl, 1-cyclohexylethyl, 2-cyclohexylethyl,ethylcyclohexyl, nonyl, 1-methyloctyl, 5-methyloctyl,1-(2'-methylpropyl)-3-methylbutyl, 3,5,5-trimethylhexyl,1,1-diethyl-2,2-dimethylpropyl, 3-cyclohexylpropyl, 1,1-dimethylheptyl,decyl, 1-methylnonyl, 1-propylheptyl, 3,7-dimethyloctyl,2,4,6-trimethylheptyl, 4-cyclohexylbutyl, butylcyclohexyl,3,3,5,5-tetramethylcyclohexyl, undecyl, 1-methyldecyl, 2-methyldecyl,2-ethylnonyl, dodecyl, 1-methylundecyl, 2-methylundecyl, 2-ethyldecyl,1-(2'-methylpropyl)-3,5-dimethylhexyl, tridecyl,2,4,6,8-tetramethylnonyl, 2-methyldodecyl, 2-ethylundecyl,1-(3'-methylbutyl)-6-methylheptyl, 1-(1'-methylbutyl)-4-methylheptyl,tetradecyl, 1-methyltridecyl, 2-methyltridecyl, 2-ethyldodecyl,2-(3'-methylbutyl)-7-methyloctyl, 2-(1'-methylbutyl)-5-methyloctyl,pentadecyl, 1-hexylnonyl, 2-methyltetradecyl, 2-ethyltridecyl,hexadecyl, 1-methylpentadecyl, 2-hexyldecyl, heptadecyl, 1-heptyldecyl,1-(1',3',3'-trimethylbutyl)-4,6,6-trimethylheptyl,1-(3'-methylhexyl)-6-methylnonyl, octadecyl, 2-heptylundecyl,2-(1',3',3'-trimethylbutyl)-5,7,7-trimethyloctyl,2-(3'-methylhexyl)-7-methyldecyl, and 2-octyldodecyl; aryl and alkylaryl groups, such as phenyl, 2-, 3-, or 4-methylphenyl, 2-, 3-, or4-ethylphenyl, 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, or 3,5-dimethylphenyl, 2-,3-, or 4-isopropylphenyl, 2-, 3-, or 4-propylphenyl, 2,3,5-,2,3,6-2,4,6-, or 3,4,5-trimethylphenyl, 2-, 3-, or 4-tert-butylphenyl,2-, 3-, or 4-sec-butylphenyl, 4- or 5-isopropyl-3-methylphenyl,4-tert-amylphenyl, 3-, 4-, or 5-methyl-2-tert-butylphenyl,pentamethylphenyl, naphthyl, 2-methylnaphthyl, 2,6-diisopropylphenyl,4-tert-octylphenyl, 2,4-, 2,6-, or 3,5-di-tert-butylphenyl,di-sec-butylphenyl, 2,6,-di-tert-butyl-4-methylphenyl, and2,4,6-tri-tert-butylphenyl; and aralkyl groups, such as benzyl, 2-, 3-,or 4-methylbenzyl, phenetyl, sec-phenetyl, 2,4-, 2,5-, 3,4- or3,5-dimethylbenzyl, 4-ethylbenzyl, 2-, 3-, or 4-methylphenetyl, α- orβ-methylphenetyl, α,α-dimethylbenzyl, 1- or 3-phenylpropyl, α- orβ-ethylphenetyl, 4-isopropylbenzyl, α-isopropylbenzyl,α,α-dimethylphenetyl, 1-, 3-, or 4-phenylbutyl, α-ethyl-α-methylbenzyl,4-butylbenzyl, 4-tert-butylbenzyl, 1,1-dimethyl-3-phenylpropyl, 1- or3-phenyl-2,2-dimethylpropyl, a-propylphenetyl, 5-phenylpentyl,naphthylmethyl, naphthylethyl, and 6-phenylhexyl.

Examples of the carbodiimides include 1,3-diisopropylcarbodiimide,1,3-di-tert-butylcarbodiimide, 1,3-dicyclohexylcarbodiimide,1,3-di-p-tolylcarbodiimide, and 1,3-(2,6-diisopropylphenyl)carbodiimide,with a preference given to 1,3-dicyclohexylcarbodiimide,1,3-di-p-tolylcarbodiimide, and1,3-bis-(2,6-diisopropylphenyl)carbodiimide.

The amount of the carbodiimide added in the present invention isnormally 0.01 to 10 parts by weight, preferably 0.05 to 5 parts byweight, based upon 100 parts by weight of the ether compounds in thepresent invention.

In addition to the above additive to remove water, the followingadditives may be added: lubricity additives, such as triaryl phosphateand/or triaryl phosphite; radical trapping additives, such as phenolcompounds or metal deactivators having chelating capacity for improvingthermal stability; and metal surface protective agents, such asbenzotriazol and/or benzotriazol derivatives.

Triaryl phosphates and triaryl phosphites used in the present inventionare those having 18-70 carbon atoms, preferably 18-50 carbon atoms.Examples of the triaryl phosphates and triaryl phosphites used in thepresent invention are set forth in Japanese Patent Laid-Open No.5-209171, column 12, lines 26 to 41. Among the examples, the followingcompounds are particularly preferable: triphenyl phosphate, tricresylphosphate, trixylenyl phosphate, tris(2,4-di-tert-butylphenyl)phosphate,triphenyl phophite, tricresyl phosphite, trixylenyl phosphite, andtris(2,4-di-tert-butylphenyl)phosphite.

The amount of triaryl phosphates and triaryl phosphites added in thepresent invention is normally 0.1 to 5.0 parts by weight, preferably 0.5to 2.0 parts by weight, based upon 100 parts by weight of the ethercompounds in the present invention.

Phenol compounds having a radical trapping capacity are those having6-100 carbon atoms, preferably 10-80 carbon atoms. Examples of thephenol compounds are set forth in Japanese Patent Laid-Open No.5-209171, column 12, line 32 to column 13, line 18. Of the examples, thefollowing compounds are particularly preferable:2,6-di-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol,4,4'-methylenebis(2,6-di-tert-butylphenol),4,4'-butylidenebis(3-methyl-6-tert-butylphenol),2,2'-methylenebis(4-ethyl-6-tert-butylphenol),2,2'-methylenebis(4-methyl-6-tert-butylphenol),4,4'-isopropylidenebisphenol, 2,4-dimethyl-6-tert-butylphenol, tetrakismethylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate!methane,1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane,1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene,2,6-di-tert-butyl-4-ethylphenol,2,6-bis(2'-hydroxy-3'-tert-butyl-5'-methylbenzyl)-4-methylphenol, bis2-(2-hydroxy-5-methyl-3-tert-butylbenzyl)-4-methyl-6-tert-butylphenyl!terephthalate,triethyleneglycol-bis3-(3,5-di-tert-butyl-5-methyl-4-hydroxyphenyl)propionate!, and1,6-hexanediol-bis 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate!.

The amount of the phenol compounds added in the present invention isnormally 0.05 to 2.0 parts by weight, preferably 0.05 to 0.5 parts byweight, based upon 100 parts by weight of the ether compounds in thepresent invention.

The metal deactivators used in the present invention is preferably thosewith a chelating capacity, and having 5-50 carbon atoms, preferably 5-20carbon atoms. Examples of the metal deactivators are set forth inJapanese Patent Laid Open No. 5-209171, column 13, line 38 to column 14,line 8. Of the examples, the following compounds are particularlypreferable: N,N'-disalicylidene-1,2-diaminoethane,N,N'-disalicylidene-1,2-diaminopropane, acetylacetone, acetoacetate,alizarine, and quinizarin.

The amount of the metal deactivators added in the present invention isnormally 0.001 to 2.0 parts by weight, preferably 0.003 to 0.5 parts byweight, based upon 100 parts by weight of the ether compounds in thepresent invention.

The benzotriazol and benzotriazol derivatives used in the presentinvention is preferably those having 6-50 carbon atoms, more preferably6-30 carbon atoms. Examples of the benzotriazol and benzotriazolderivatives are set forth in Japanese Patent Laid Open No. 5-209171,column 13, lines 9 to 29. Of the examples, benzotriazol and5-methyl-1H-benzotriazol are particularly preferable.

The amount of benzotriazol and/or benzotriazol derivatives added in thepresent invention is normally 0.001 to 0.1 parts by weight, preferably0.003 to 0.03 parts by weight, based upon 100 parts by weight of theether compounds in the present invention.

Other additives conventionally used for lubricating oil, such asantioxidants, extreme pressure additives, oiliness improvers, anddefoaming agents, may be added according to necessity. For examples,antioxidants usable in the present invention are amine-basedantioxidants, such as p,p-dioctylphenylamine, monooctyldiphenylamine,phenothiazine, 3,7-dioctylphenothiazine, phenyl-1-naphthylamine,phenyl-2-naphthylamine, alkylphenyl-1-naphthylamine, andalkylphenyl-2-naphthylamine; sulfur-based antioxidants, such as alkyldisulfides, thiodipropionic acid esters, and benzothiazoles; and zinccompounds, such as zinc dialkyl dithiophosphate and zinc diaryldithiophosphate. The amounts of the above additives are 0.05 to 2.0parts by weight, based on 100 parts by weight of the ether compounds inthe present invention.

Examples of the extreme-pressure additives and oiliness agents usable inthe present invention are zinc compounds, such as zinc dialkyldithiophosphate and zinc diaryl dithiophosphate; sulfur compounds, suchas thiodipropionic acid esters, dialkyl sulfide, dibenzyl sulfide,dialkyl polysulfide, alkyl mercaptan, dibenzothiophene, and2,2'-dithiobis(benzothiazole): phosphorus compounds, such as trialkylphosphite, and trialkyl phosphate; chlorine compounds, such aschlorinated paraffin; molybdenum compounds, such as molybdenumdithiocarbamate, molybdenum dithiophosphate, and molybdenum disulfide;fluorine compounds, such as perfluoroalkyl polyethers, trifluorochloroethylene polymers, graphitefluoride; silica compounds, such as fattyacid-modified silicone; and graphite. The amount added in the presentinvention is 0.05 to 10 parts by weight, based upon 100 parts by weightof the ether compound of the present invention.

Examples of defoaming agents usable in the present invention aresilicone oils, such as dimethylpolysiloxane; and organosilicates, suchas diethyl silicate. The amount added in the present invention is 0.0005to 1 parts by weight, based on 100 parts by weight of the ether compoundof the present invention.

Additives stabilizing freon refrigerants, such as organic tin compoundsand boron compounds, may be added in the present invention. The amountadded in the present invention is 0.001 to 10 parts by weight, based on100 parts by weight of the ether compounds in the present invention.

The mixing ratio of a hydrofluorocarbon with a refrigeration oilcontaining the ether compounds in the present invention as a base oil orwith a refrigeration oil containing the above base oil to whichadditives are further added (hydrofluorocarbon/oil) is normally 50/1 to1/20 (weight ratio), preferably 10/1 to 1/5 (weight ratio). When themixing ratio exceeds 50/1, the viscosity of the mixed solution ofhydrofluorocarbon and oil becomes low, thereby making it likely to haveundesirably poor lubricity. When the mixing ratio is lower than 1/20,the refrigeration ability is likely to become undesirably poor.

The hydrofluorocarbons used in the present invention includedifluoromethane (HFC32), 1,1-difluoroethane (HFC152a),1,1,1-trifluoroethane (HFC143a), 1,1,1,2-tetrafluoroethane (HFC134a),1,1,2,2-tetrafluoroethane (HFC134) and pentafluoroethane (HFC125), witha particular preference given to 1,1,1,2-tetrafluoroethane,pentafluoroethane, and difluoromethane.

EXAMPLES

The present invention will be further described by means of Examples,without intending to restrict the scope of the present inventionthereto.

Example 1-1 Synthesis of 1,6-di-O-(3,5,5-trimethylhexyl)sorbitolCompound (1b)!

1) 1.2:3.4:5.6-tri-O-(3,5,5-trimethylhexylidene)sorbitol: Compound (1a)

In a 3-liter reaction vessel equipped with a thermometer, a refluxcondenser, a Dean and Stark trap, a calcium chloride tube, and astirrer, 170.76 g (0.937 mol) of D-sorbitol, 400 g (2.812 mol) of3,5,5-trimethylhexanal, 1.78 g (0.00936 mol) of p-toluene sulfonic acid1 hydrate, and 400 ml of hexane were placed and heated with stirring. Areaction was carried out at a temperature of from 79° to 81° C. for 8hours while distilling off a theoretical amount of water. After beingcooled to 70° C., the reaction mixture was neutralized by adding 1.99 g(0.0188 mol) of sodium carbonate, and stirred at 70° C. for 30 minutes.After 100 g of water was added to the mixture and stirred at 60° C. for30 minutes, the mixture was allowed to stand to separate into twolayers. After the lower layer was discarded, the remaining mixture waswashed with 100 g of saturated brine, and evaporated to give 529.51 g ofcrude Compound (1a).

The obtained product was subjected to a reduced-pressure distillationand a forerun was discarded. 500.87 g of the residue was dissolved in500 ml of hexane. The hexane solution was subjected to an adsorptiontreatment by passing through 25.04 g (5% by weight to the residue) ofactivated clay on a filter (PTFE, 0.2 μm) under pressure. After washingthe clay cake with hexane, the hexane in the solution was completelydistilled away to give 501.14 g of Compound (1a) (yield: 96.4%).

The product has a purity of 96.3% as determined by gas chromatography,and a hydroxyl value of 27.2. (theoretical value of 0).

2) 1,6-di-O-(3,5,5-trimethylhexyl)sorbitol: Compound (1b)

In a 1-liter autoclave, 487.1 g (0.878 mol) of the obtained Compound(1a), and 9.74 g (2% by weight) of 5% Pd/C catalyst were placed, the 5%Pd/C catalyst being prepared by drying a commercially available productwith 50% moisture content (5% Pd carbon powder with 50% moisturecontent, E-type, pH 6.0, manufactured by N. E. Chemcat Corp.) at roomtemperature for one day under reduced pressure using a vacuum pump. Thetemperature of the autoclave was raised with stirring the mixture undera hydrogen pressure of 20 kg/cm². Then the mixture was kept for 8 hoursunder a hydrogen pressure of 200 kg/cm² at 190° C. The hydroxyl value atthe completion of the reaction was 243.3 theoretical value: 300.9 (as anether alcohol with an average alkyl substituent number of 3.0)!. Thereaction mixture was dissolved in 300 ml of isopropanol, and the mixturewas subjected to a pressure-filtration through a membrane filter (PTFE,0.2 μm). The filtrate was evaporated to give 475.85 g of a crude mixtureof polyol ethers (yield of crude mixture: 96.6%). The composition of themixture determined by gas chromatography was as follows: 19% of dialkylproduct; 47% of trialkyl product; 18% of tetraalkyl product; 3% ofmonoalkyl product; and 2% of pentaalkyl product. 200 g of the crudemixture was weighed and subjected to a silica gel column chromatographyfor purification, in which 18.2 g of purified Compound (1b) was obtainedby elution with hexane/ethanol 93/7 (vol/vol)! after elution of Compound(3) with hexane/ethanol 97/3 (vol/vol)! and elution of Compound (2) withhexane/ethanol 95/5 (vol/vol)!. The purity of Compound (1b) wasdetermined to be 90.5% by gas chromatography, and the hydroxyl value ofthe compound was 471 (theoretical value: 517).

IR (NEAT, cm⁻¹): 3465 (O-H stretching), 2954 (C-H stretching), 1473,1395, 1368 (C-H deformation), 1122 (C-O stretching)

¹ H NMR (CDCl₃, δppm): 0.77-1.35 (28H, multiplet, --CH(CH₃)CH₂ C(CH₃)₃)1.35-1.75 (2H, multiplet, --CH₂ CH(CH₃)CH₂ C(CH₃)₃) 3.03 (4H, singlet,--OH) 3.43-4.02 (12H, multiplet, --CH(OH)--, --CH₂ OCH₂ --)

MASS (FD): 436 (M+1)

Example 1-2 Synthesis of 1,3,6-tri-O-(3,5,5-trimethylhexyl)sorbitolCompound (2)!

100 g of the crude mixture of polyol ethers obtained in Example 1-1 waspurified similarly to Example 1-1 by silica gel column chromatography.That is, after Compound (3) was eluted with hexane/ethanol 97/3(vol/vol)!, Compound (2) was eluted using a hexane/ethanol 95/5(vol/vol)! developing solvent. As a result, 32.3 g of Compound (2) wasobtained. The purity of Compound (2) was determined to be 93.3% by gaschromatography, and the hydroxyl value of the compound was 280(theoretical value: 301).

IR (NEAT, cm⁻¹): 3466 (O-H stretching), 2956 (C-H stretching), 1473,1395, 1368 (C-H deformation), 1122 (C-O stretching)

¹ H NMR (CDCl₃, δppm): 0.77-1.35 (42H, multiplet, --CH(CH₃)CH₂ C(CH₃)₃)1.35-1.80 (9H, multiplet, --CH₂ CH(CH₃)CH₂ C(CH₃)₃) 3.40-4.00 (14H,multiplet, --CH(OH)--, --CH₂ OCH₂ --)

MASS (FD): 688 (M+1)

Example 1-3 Synthesis of 1,3,6,x-tetra-O-(3,5,5-trimethylhexyl)sorbitolCompound (3)! (x represents a figure of 2, 4 or 5; x in the Examplesbelow has the same definition)

100 g of the crude mixture of polyol ethers obtained in Example 1-1 waspurified similarly to Example 1-1 by silica gel column chromatographyusing a hexane/ethanol 97/3 (vol/vol)! developing solvent to give 24.0 gof Compound (3). The purity of Compound (3) was determined to be 83.5%by gas chromatography, and the hydroxyl value of the compound was 174(theoretical value: 163).

IR (NEAT, cm⁻¹): 3465 (O-H stretching), 2954 (C-H stretching), 1473,1394, 1367 (C-H deformation), 1120 (C-O stretching)

MASS (FD): 351 (M+1)

Example 1-4 Synthesis of a mixture of1-O-(3,5,5-trimethylhexyl)sorbitol,1,6-di-O-(3,5,5-trimethylhexyl)sorbitol,1,3,6-tri-O-(3,5,5-trimethylhexyl)sorbitol,1,3,6x-tetra-O-(3,5,5-trimethylhexyl)sorbitol, and1,3,6,x,y-penta-O-(3,5,5-trimethylhexyl)sorbitol (ether alcohols havingan average alkyl substituent number of 3.1) Compounds (4)!

(y represents a figure of 2, 4, or 5, the figure being different from x;y in the Examples below has the same definition)

200 g of the crude mixture of polyol ethers obtained in Example 1-1 waspurified by heating under a reduced pressure (192° C. at 0.6 mmHg) toremove low-boiling point components. As a result, 178 g of Compounds (4)was obtained (yield: 89.2%). The composition of the obtained Compounds(4) as determined by gas chromatography was as follows: 3% of monoalkylproduct; 21% of dialkyl product; 53% of trialkyl product; 20% oftetraalkyl product; and 2% of pentaalkyl product. The hydroxyl value ofthe mixture was 282 (ether alcohols with an average alkyl substituentnumber of 3.1).

IR (NEAT, cm⁻¹): 3466 (O-H stretching), 2955 (C-H stretching), 1473,1395, 1367 (C-H deformation), 1118 (C-O stretching)

Example 1-5 Synthesis of a mixture of1-mono-O-(3,5,5-trimethylhexyl)sorbitol,1,6-di-O-(3,5,5-trimethylhexyl)sorbitol,1,3,6-tri-O-(3,5,5-trimethylhexyl)sorbitol,1,3,6,x-tetra-O-(3,5,5-trimethylhexyl)sorbitol, and1,3,6,x,y-penta-O-(3,5,5-trimethylhexyl)sorbitol, (ether alcohols havingan average alkyl substituent number of 2.0) Compounds (5)!

In a 1-liter autoclave, 480 g (0.865 mol) of1.2:3.4:5.6-tri-O-(3,5,5-trimethylhexylidene)sorbitol (1a), 78.8 g(0.433 mol) of D-sorbitol, and 9.74 g (2% by weight) of 5% Pd/C catalystwere placed, the 5% Pd/C catalyst being prepared by drying acommercially available product with 50% moisture content (5% Pd carbonpowder with 50% moisture content, E-type, pH 6.0, manufactured by N. E.Chemcat Corp.) at room temperature for one day under a reduced pressureusing a vacuum pump. The temperature of the autoclave was raised withstirring the mixture under a hydrogen pressure of 20 kg/cm². Then themixture was kept for 25 hours under a hydrogen pressure of 200 kg/cm² at190° C. The reaction mixture was dissolved in 300 ml of isopropanol, andsubjected to a pressure-filtration through a membrane filter (PTFE, 0.2μm). The filtrate was evaporated to give 532.0 g of a crude mixture ofpolyol ethers (yield of crude mixture: 95.1%).

The crude mixture of polyol ethers obtained was purified by heatingunder a reduced pressure (182°-207° C. at 0.6 mmHg) to removelow-boiling point components. As a result, 484 g of Compounds (5) wasobtained (yield: 91.0%).

The composition of the obtained Compounds (5) as determined by gaschromatography was as follows: 34% of monoalkyl product; 47% of dialkylproduct; 16% of trialkyl product; and 1% of tetraalkyl product. Thehydroxyl value of the mixture was 521 (ether alcohols with an averagealkyl substituent number of 2.0).

Example 1-6 Synthesis of2,3,4,5-tetra-O-methyl-1,6-di-O-(3,5,5-trimethylhexyl)sorbitol Compound(6)!

In a 1-liter reaction vessel equipped with a thermometer, a refluxcondenser, a dropping funnel, and a stirrer, 7.3 g (0.18 mol) of sodiumhydride (content: 60%, oily) was placed. The sodium hydride was washedwith 50 ml of hexane by decantation. Then, 320 ml of a mixed solvent of1,2-dimethoxyethane/dimethylsulfoxide (3/1, vol/vol) was added to thevessel. Then, 17.0 g (0.039 mol) of Compound (1b) obtained in Example1-1 was dissolved in 16 ml of the mixed solvent and added dropwise tothe vessel with stirring over 10 minutes at room temperature. Thereaction mixture was heated to 50° C., and stirred for 1 hours withmaintaining the temperature. After the mixture was cooled to 40° C.,22.9 g (0.18 mol) of dimethyl sulfate was added dropwise over 20 minuteswith the temperature maintained below 50° C. After the mixture wasstirred for another 1 hour at 50° C. and cooled, 72.0 g (0.18 mol) of10% aqueous solution of sodium hydroxide was added. Then the mixture wasstirred at 70° to 80° C. for 1 hour. After cooling, 100 ml of water wasadded to allow phase separation. The aqueous layer was extracted twicewith 150 ml of diethyl ether, and the organic layer was combined withthe ether extracts. The mixture was washed three times with 100 ml ofsaturated brine and dried over anhydrous sodium sulfate. Then, thesolvent was distilled away with an evaporator to give 21.2 g of oilysubstance. This substance was purified by silica gel columnchromatography using a hexane/diethyl ether 90/10 (vol/vol)! developingsolvent and subjected to a reduced-pressure distillation (boiling point:179° C. at 0.35 mmHg) to give 6.8 g of Compound (6). The purity ofCompound (6) was determined to be 99.7% by gas chromatography.

IR (NEAT, cm⁻¹): 2950 (C-H stretching), 1473, 1368 (C-H deformation),1116 (C-O stretching)

¹ H NMR (CDCl₃, δppm): 0.80-1.33 (28H, multiplet, --CH(CH₃)CH₂ C(CH₃)₃)1.33-1.80 (6H, multiplet, --CH₂ CH(CH₃)CH₂ C(CH₃)₃) 3.35-3.80 (24H,multiplet, --CH(OCH₃)--, --CH₂ OCH₂ --)

Example 1-7 Synthesis of2,4,5-tri-O-methyl-1,3,6-tri-O-(3,5,5-trimethylhexyl)sorbitol Compound(7)!

In a 1-liter reaction vessel equipped with a thermometer, a refluxcondenser, a dropping funnel, and a stirrer, 4.9 g (0.12 mol) of sodiumhydride (content: 60%, oily) was placed. The sodium hydride was washedwith 50 ml of hexane by decantation. Then, 320 ml of a mixed solvent of1,2-dimethoxyethane/dimethylsulfoxide (3/1, vol/vol) was added to thevessel. 15.3 g (0.027 mol) of Compound (2) obtained in Example 1-2 wasdissolved in 12 ml of the mixed solvent and added dropwise to the vesselwith stirring over 10 minutes at room temperature. The reaction mixturewas heated to 50° C. and stirred for 30 minutes with maintaining thetemperature. After the mixture was cooled to 40° C., 15.5 g (0.12 mol)of dimethyl sulfate was added dropwise over 1 hour with the temperaturemaintained below 50° C. After the mixture was stirred for another 1 hourat 50° C. and cooled, 48.0 g (0.12 mol) of 10% aqueous solution ofsodium hydroxide was added. Then the mixture was stirred at 70° to 80°C. for 1 hour. After cooling, the mixture was allowed to phase separate.The aqueous layer was extracted twice with 100 ml of diethyl ether, andthen the organic layer was combined with the ether extracts. The mixturewas washed three times with 50 ml of saturated brine and dried overanhydrous sodium sulfate. Then, the solvent was distilled away with anevaporator to give 16.9 g of oily substance. This substance was purifiedby silica gel column chromatography using a hexane/diethyl ether 90/10(vol/vol)! developing solvent to give 12.6 g of Compound (7). The purityof Compound (7) was determined to be 98.4% by gas chromatography.

IR (NEAT, cm⁻¹): 2956 (C-H stretching), 1470, 1368 (C-H deformation),1194 (C-O stretching)

¹ H NMR (CDCl₃, δppm): 0.78-1.10 (42H, multiplet, --CH(CH₃)CH₂ C(CH₃)₃)1.16-1.78 (9H, multiplet, --CH₂ CH(CH₃)CH₂ C(CH₃)₃) 3.23-3.85 (23H,multiplet, --CH(OCH₃)--, --CH₂ OCH₂ --)

Example 1-8-1 Synthesis of a mixture of2,3,4,5,6-penta-O-methyl-1-O-(3,5,5-trimethylhexyl)sorbitol,2,3,4,5-tetra-O-methyl-1,6-di-O-(3,5,5-trimethylhexyl)sorbitol,2,4,5-tri-O-methyl-1,3,6-tri-O-(3,5,5-trimethylhexyl)sorbitol,di-O-methyl-1,3,6,x-tetra-O-(3,5,5-trimethylhexyl)sorbitol, andO-methyl-1,3,6,x,y-penta-O-(3,5,5-trimethylhexyl)sorbitol methyl-cappedether alcohols having an average alkyl substituent number of 2.0)Compounds (8-1)!

In a 3-liter reaction vessel equipped with a thermometer, a refluxcondenser, a dropping funnel, and a stirrer, 117 g (3.06 mol) of sodiumhydride (content: 60%, oily) was placed. The sodium hydride was washedwith 400 ml of hexane by decantation. Then, 1.5 liters of toluene wasadded to the vessel.

220 g of Compounds (5) obtained in the same way as in Example 1-5 (etheralcohol with hydroxyl value of 521 and average alkyl substituent numberof 2.0), i.e., a mixture of mono-, di-, tri-, tetra-, andpenta-O-(3,5,5-trimethylhexyl)sorbitol, was dissolved in 300 ml oftoluene, and added dropwise to the vessel over 30 minutes at 24° to 36°C. The reaction mixture was heated to 90° to 97° C. and stirred for 30minutes with maintaining the temperature. After the mixture was cooledto 40° C., 386 g (3.06 mol) of dimethyl sulfate was added dropwise over2.5 hours with the temperature maintained below 60° C. After the mixturewas stirred for another 1 hour at 60° C. and cooled, 898 g (3.37 mol) of15% aqueous solution of sodium hydroxide was added. Then the mixture wasstirred at 80° C. for 1 hour. After cooling, the mixture was allowed tophase separate. The water layer was extracted once with 300 ml oftoluene, and the organic layer was combined with the toluene. Themixture was washed three times with 40 ml of saturated brine. Then, themixture was dried over anhydrous sodium sulfate, and the solvent wasdistilled away with an evaporator to give 248 g of oily substance. Thesubstance was purified by heating at 185° to 190° C. under a reducedpressure (0.7 mmHg) for 30 minutes to remove low-boiling pointcomponents. As a result 226 g of Compounds (8-1) was obtained. Thecomposition of the obtained Compounds (8-1) as determined by gaschromatography was as follows: 34% of monoalkyl product; 47% of dialkylproduct; 16% of trialkyl product; and 1% of tetraalkyl product.

IR (NEAT, cm⁻¹): 2956 (C-H stretching), 1473, 1368 (C-H deformation),1104 (C-O stretching)

Example 1-8-2 Synthesis of a mixture of2,3,4,5-tetra-O-methyl-1,6-di-O-(3,5,5-trimethylhexyl)sorbitol,2,4,5-tri-O-methyl-1,3,6-tri-O-(3,5,5-trimethylhexyl)sorbitol,di-O-methyl-1,3,6,x-tetra-O-(3,5,5-trimethylhexyl)sorbitol, and2,3,4,5,6-penta-O-methyl-1-O-(3,5,5-trimethylhexyl)sorbitol(methyl-capped ether alcohols having an average alkyl substituent numberof 3.1) Compounds (8-2)!

In a 2-liter reaction vessel equipped with a thermometer, a refluxcondenser, a dropping funnel, and a stirrer, 25.35 g (1.06 mol) ofsodium hydride powder and 500 ml of toluene were placed. 100 g (0.2 mol)of Compounds (4) obtained in the same way as in Example 1-4, i.e., amixture of mono-, di-, tri-, and tetra-O-(3,5,5-trimethylhexyl)sorbitol,was dissolved in 100 ml of toluene, and added dropwise to the vesselover 30 minutes with stirring at room temperature under nitrogenatmosphere. Then, 200 ml of toluene was added to the vessel. Thereaction mixture was heated to 110° C. and refluxed with stirring for 30minutes at 110° C. After the mixture was cooled to 50° C., 133.22 g(1.06 mol) of dimethyl sulfate was added dropwise over 1 hour with thetemperature maintained below 50° C. 600 ml of toluene was further addedand the mixture was matured for 1 hour at 80° C. After the mixture wascooled and 422.5 g of 10% aqueous solution (1.06 mol) of sodiumhydroxide was added, the mixture was stirred at 70° to 80° C. for 30minutes. After being cooled to room temperature, the mixture was allowedto phase separate. The lower layer was discarded. The upper layer waswashed four times with 200 ml of saturated brine. Then, the mixture wasdried over anhydrous sodium sulfate, and subjected to adsorptiontreatment with 2.2 g of activated carbon (2% by weight of activatedcarbon based on the theoretical yield). After filtration, toluene in thefiltrate was distilled away to give oily substance. The oily substancewas further heated under a reduced pressure of 0.7 mmHg and the forerunwas discarded until the internal temperature reached 200° C. As aresult, 70.4 g of Compounds (8-2) was obtained (yield: 64.4%).

The purity of the Compounds (8-2) was determined to be 96.1% by gaschromatography.

The composition of the mixture was as follows: 3.5% by weight of2,3,4,5,6-penta-O-methyl-1-O-(3,5,5-trimethylhexyl)sorbitol; 37.6% byweight of2,3,4,5-tetra-O-methyl-1,6-di-O-(3,5,5-trimethylhexyl)sorbitol; 42.9% byweight of 2,4,5-tri-O-methyl-1,3,6-tri-O-(3,5,5-trimethylhexyl)sorbitol;and 12.1% by weight ofdi-O-methyl-1,3,6,x-tetra-O-(3,5,5-trimethylhexyl)sorbitol.

Example 1-9 Synthesis of16-di-O-(1-methylpropyl)-O-(1-methylpropylidene)sorbitol Compound (9b)!

1) 1.2:3.4:5.6-tri-O-(1-methylpropylidene)sorbitol: Compound (9a)

In a 3-liter reaction vessel equipped with a thermometer, a refluxcondenser, a Dean and Stark trap, a calcium chloride tube, and astirrer, 336.84 g (1.849 mol) of D-sorbitol, 800 g (11.094 mol) ofmethyl ethyl ketone, 17.58 g (0.092 mol) of p-toluene sulfonic acid 1hydrate, and 200 ml of hexane were placed and heated with stirring. Areaction was carried out at a temperature of from 69° to 79° C. for 8hours while distilling off a theoretical amount of water. After beingcooled to 60° C., the reaction mixture was neutralized by adding 19.60 g(0.185 mol) of sodium carbonate, and stirred at 60° C. for 30 minutes.After 200 g of water was added to the mixture and stirred at for 60° C.for 30 minutes, the mixture was allowed to stand to separate into twolayers. After the lower layer was discarded, the remaining mixture waswashed with 200 g of saturated brine, and evaporated to give 643.75 g ofcrude Compound (9a). The crude compound was subjected to areduced-pressure distillation to give 606.71 g of Compound (9a) (yield:95.3%). The obtained Compound (9a) had a boiling point of 136° to 140°C. at 0.6 mmHg, purity as determined by gas chromatography of 97.3%, anda hydroxyl value of 12.9 (theoretical value: 0).

2) 1,6-di-O-(1-methylpropyl)-O-(1-methylpropylidene)sorbitol: Compound(9b)

In a 1-liter autoclave, 571.5 g (1.659 mol) of Compound (9a) obtainedabove, and 11.43 g (2% by weight) of 5% Pd/C catalyst were placed, the5% Pd/C catalyst being prepared by drying a commercially availableproduct with 50% moisture content (5% Pd carbon powder with 50.0%moisture content, E-type, pH 6.0, manufactured by N. E. Chemcat Corp.)at room temperature for one day under a reduced pressure using a vacuumpump. The temperature of the autoclave was raised with stirring themixture under a hydrogen pressure of 20 kg/cm². Then the mixture waskept for 15 hours under a hydrogen pressure of 200 kg/cm² with theheating maintained at 190° C. The hydroxyl value at the completion ofthe reaction was 403.5 theoretical value: 480.23 (as an ether alcoholwith an average alkyl substituent number of 3.0)!. The reaction mixturewas dissolved in 200 ml of isopropanol, and the mixture was subjected toa pressure-filtration through a membrane filter (PTFE, 0.2 μm). Thefiltrate was evaporated to give 551.34 g of a crude Compound (9b) (yieldof crude compound: 96.5%). The composition of the crude compounddetermined by gas chromatography was as follows: 16% of dialkyl ether;20% of trialkyl ether; 51% of dialkyl ether monoketal; 10% of trialkylether monoketal; and 1% of tetraalkyl ether. 500 g of the crude compoundwas dissolved in 500 ml of hexane, which was washed three times withmethanol/water (200 ml/200 ml), three times with methanol/water (200ml/100 ml), and four times with methanol/water (100 ml/100 ml). Theupper hexane layer obtained was evaporated to give 251.84 g of partiallypurified hydrogenated compound.

The obtained compound was dissolved in 250 ml of hexane and purified bysilica gel column chromatography. The fractions eluted withhexane/ethanol (99/1) were collected and evaporated to give 131.92 g ofCompound (9b). The obtained Compound (9b) has a purity of 97.7% asdetermined by gas chromatography, and a hydroxyl value of 327.5(theoretical value: 322.01).

IR (NEAT, cm⁻¹): 3492 (O-H stretching), 2972, 2936, 2884 (C-Hstretching), 1468, 1378 (C-H deformation), 1082 (C-O stretching)

¹ H NMR (CDCl₃, δppm): 0.92 (9H, triplet, --CH₂ CH₃) 1.12 (6H, doublet,--CH₂ CH₃) 1.38 (3H, singlet, (--O--)₂ C(CH₃)CH₂ CH₃) 1.43-1.80 (6H,multiplet, --CH₂ CH₃) 2.85 (2H, singlet, --OH) 3.29-4.33 (10H,multiplet, --O--CH₂ --, --O--CH--)

MASS (FD): 349 (M+1)

Example 1-10 Synthesis of 1,3,6-tri-O-(1-methylpropyl)sorbital Compound(10)!

251.84 g of the partially purified hydrogenated compound obtained inExample 1-9 was dissolved in 250 ml of hexane and purified by silica gelcolumn chromatography. That is, after Compound (9b) was eluted withhexane/ethanol (99/1), fractions eluted with hexane/ethanol (95/5) werecollected and evaporated to give 55.42 g of Compound (10). The obtainedcompound had a purity of 97.3% as determined by gas chromatography and ahydroxyl value of 453.1 (theoretical value of 480.24).

IR (NEAT, cm⁻¹): 3464 (O-H stretching), 2972, 2932, 2880 (C-Hstretching), 1466, 1380 (C-H deformation), 1086 (C-O stretching)

¹ H NMR (CDCl₃, δppm): 0.92 (9H, triplet, --CH₂ CH₃) 1.13 (9H, doublet,--CHCH₃) 1.32-1.78 (6H, multiplet, --CH₂ CH₃) 3.13 (3H, broad singlet,--OH) 3.30-4.02 (--O--CH₂ --, --O--CH--)

MASS(FD): 351 (M+1)

Example 1-11 Synthesis of1,6-di-O-(1-methylpropyl)-di-O-methyl-O-(1-methylpropylidene)sorbitolCompound (11)!

In a 1-liter reaction vessel equipped with a thermometer, a refluxcondenser, a dropping funnel, and a stirrer, 12.38 g (0.516 mol) ofsodium hydride powder and 300 ml of toluene were placed. 70 g (0.201mol) of Compound (9b) obtained in Example 1-9 was dissolved in 100 ml oftoluene, and added dropwise to the vessel over 20 minutes with stirringat room temperature under nitrogen atmosphere. The reaction mixture washeated to 110° C. and refluxed with stirring for 30 minutes. After themixture was cooled to 50° C., 65.08 g (0.516 mol) of dimethyl sulfatewas added dropwise over 1 hour with the temperature maintained at 50° C.The mixture was matured for 1 hour at 80° C. After the mixture wascooled and 206.4 g of 10% aqueous solution (0.516 mol) of sodiumhydroxide was added, the mixture was stirred at 70° to 80° C. for 30minutes. After being cooled to room temperature, the mixture wasextracted with 200 ml of ether, washed twice with 100 ml of saturatedbrine, dried over anhydrous sodium sulfate, and evaporated to give 76.72g of viscous oily substance. The substance obtained was subjected to areduced-pressure distillation to give 68.83 g of Compound (11) (yield:92.1%). The obtained Compound (11) had a boiling point of 127° to 128°C. at 0.4 mmHg, a purity of 99.0% as determined by gas chromatography,and a hydroxyl value of 0.67 (theoretical value: 0).

IR (NEAT, cm⁻¹): 2974, 2925 (C-H deformation), 1470, 1377, 1341 (C-Hdeformation), 1089 (C-O stretching)

¹ H NMR (CDCl₃, δppm): 0.90 (9H, triplet, --CH₂ CH₃) 1.10-1.20 (6H,multiplet, --CH(CH₃ CH₂ CH₃) 1.29-1.42 (3H, multiplet, (--O--)₂C(CH₃)CH₂ CH₃) 1.42-1.80 (6H, multiplet, --CH₂ CH₃) 3.29-3.80 (14H,multiplet, --CH₂ --O--CH(CH₃)CH₂ CH₃, CH--O--CH₃)

Example 1-12 Synthesis of2,4,5-tri-O-ethyl-1,3,6-tri-O-(1-methylpropyl)sorbitol Compound (12)!

In a 300-milliliter reaction vessel equipped with a thermometer, areflux condenser, a dropping funnel, and a stirrer, 3.70 g (0.154 mol)of sodium hydride powder and 100 ml of toluene were placed. 12 g (0.0342mol) of Compound (10b) obtained in Example 1-10 was dissolved in 50 mlof toluene, and added dropwise to the vessel over 20 minutes withstirring at room temperature under nitrogen atmosphere. The reactionmixture was heated to 110° C. and refluxed with stirring for 30 minuteswith maintaining the temperature. After the mixture was cooled to 50°C., 23.75 g (0.154 mol) of dimethyl sulfate was added dropwise over 45minutes with the temperature maintained at 50° C. The mixture wasmatured for 2 hours at 80° C. After the mixture was cooled and 61.6 g(0.154 mol) of 10% aqueous solution of sodium hydroxide was added, themixture was stirred at 70° to 80° C. for 30 minutes. After the mixturewas cooled to room temperature, the lower layer was discarded, and theupper toluene layer was washed twice with 50 ml of saturated brine,dried over anhydrous sodium sulfate, and evaporated to give 14.8 g ofviscous oily substance. The substance obtained was subjected to areduced-pressure distillation to give 13.69 g of Compound (12) (yield:92.0%). The obtained Compound (12) had a boiling point of 145° to 146°C. at 0.5 mmHg, a purity of 96.2% as determined by gas chromatography,and a hydroxyl value of 0.5 (theoretical value: 0).

IR (NEAT, cm⁻¹): 2974, 2932, 2878 (C-H stretching), 1467, 1377, 1341(C-Hdeformation), 1110 (C-O stretching)

¹ H NMR (CDCl₃, δppm): 0.82-1.08 (9H, triplet, --CH(CH₃)CH₂ CH₃)1.08-1.80 (24H, multiplet, --CH(CH₃)CH₂ CH₃, --OCH₂ CH₃) 3.21-4.00 (17H,multiplet, --CH--O--CH₂ --, --CH--OCH(CH₃)--)

Example 1-13 Synthesis of1,6-di-O-(1,3-dimethylbutyl)-O-(1,3-dimethylbutylidene)sorbitol Compound(13b)!

1) 1.2:3.4:5.6-tri-O-(1,3-dimethylbutylidene)sorbitol: Compound (13a)

In a 3-liter reaction vessel equipped with a thermometer, a refluxcondenser, a Dean and Stark trap, a calcium chloride tube, and astirrer, 363.76 g (1.997 mol) of D-sorbitol, 1200 g (11.981 mol) ofmethyl isobutyl ketone, 18.99 g (0.0998 mol) of p-toluene sulfonic acid1 hydrate, and 300 ml of hexane were placed and heated with stirring. Areaction was carried out at a temperature of from 93° to 98° C. for 23hours while distilling off a predetermined amount of water. After beingcooled to 60° C., the reaction mixture was neutralized by adding 21.16 g(0.1996 mol) of sodium carbonate, and stirred at 60° C. for 30 minutes.After 200 g of water was added to the mixture and stirred at 60° C. for30 minutes, the mixture was allowed to stand to separate into twolayers. After the lower layer was discarded, the remaining mixture waswashed with 200 g of saturated brine and evaporated to give 736.65 g ofcrude Compound (13a). The obtained crude Compound (13a) was subjected toa reduced-pressure distillation and a forerun was discarded. 657.62 ofthe residue obtained was subjected to an adsorption treatment by passingthrough 33 g (5% by weight to the residue) of activated clay on a filter(PTFE, 0.2 μm) by a pressure filtration. As a result, 637.44 g ofCompound (13a) was obtained (yield: 74.5%).

The purity of Compound (13a) as determined by gas chromatography was96.1%, and a hydroxyl value was 34.3 (theoretical value: 0).

2) 1,6-di-O-(1,3-dimethylbutyl)-O-(1,3-dimethylbutylidene)sorbitol:Compound (13b)

In a 1-liter autoclave, 612 g (1.428 mol) of Compound (13a) obtainedabove, and 12.24 g (2% by weight) of 5% Pd/C catalyst were placed, the5% Pd/C catalyst being prepared by drying a commercially availableproduct with 50% moisture content (5% Pd carbon powder with 50.0%moisture content, E-type, pH 6.0, manufactured by N. E. Chemcat Corp.)at room temperature for one day under a reduced pressure using a vacuumpump. The temperature of the autoclave was raised with stirring themixture under a hydrogen pressure of 20 kg/cm². Then the mixture waskept for 10 hours under a hydrogen pressure of 200 kg/cm² at 190° C. Thehydroxyl value at the completion of the reaction was 366.9 theoreticalvalue: 387.25 (as an ether alcohol with an average alkyl substituentnumber of 3.0)!. The reaction mixture was dissolved in 200 ml of hexane,and the mixture was subjected to a pressure-filtration through amembrane filter (PTFE, 0.2 μm). The filtrate was evaporated to give482.73 g of hydrogenated CompOund (13b) (yield: 77.8%). The compositionof the hydrogenated compound determined by gas chromatography was asfollows: 21% of dialkyl ether; 20% of trialkyl ether; 37% of dialkylether monoketal; and 8% of trialkyl ether monoketal. 360 g of thecompound was purified by silica gel column chromatography using ahexane/ethanol (vol/vol=97/3) developing solvent to give 66.0 g ofCompound (13b). The purity of the obtained Compound (13b) as determinedby gas chromatography was 98.3%, and the hydroxyl value was 267(theoretical value: 259).

IR (NEAT, cm⁻¹): 3436 (O-H stretching), 2960, 2878 (C-H stretching),1470, 1377 (C-H deformation), 1092 (C-O stretching)

¹ H NMR (CDCl₃, δppm): 0.80-1.09 (18H, multiplet, --CH(CH₃)₂) 0.80-1.30(9H, multiplet, --OCH(Ch₃)CH₂ --, (--O--)₂ C(CH₃)CH₂ --) 1.30-1.65 (8H,multiplet, --CH₂ CH(CH₃)₂) 1.65-1.82 (2H, multiplet, --CH(CH₃)₂)2.36-2.82 (2H, broad singlet, --OH) 3.33-4.40 (10H, multiplet, --CHOCH₂--, --CH--O--)

MASS (FD): 433 (M+1)

Example 1-14 Synthesis of 1,6-di-O-(1,3-dimethylbutyl)sorbitol Compound(14)!

The hydrogenated compound obtained in Example 1-13 was purified byfurther carrying out silica gel column chromatography. That is, afterCompound (13b) was eluted with hexane/ethanol (vol/vol=97/3), Compound(14) was eluted with a hexane/ethanol (vol/vol=95/5) developing solvent.As a result, 57.9 g of Compound (14) was obtained. The purity ofCompound (14) was determined to be 83.7% by gas chromatography, and thehydroxyl value of the compound was 614 (theoretical value: 641).

IR (NEAT, cm⁻¹): 3436 (O-H stretching), 2962, 2873 (C-H stretching),1470, 1377 (C-H deformation), 1089 (C-O stretching)

¹ H NMR (CDCl₃, δppm): 0.85-1.02 (12H, multiplet, --CH(CH₃)₃) 1.15 (6H,doublet, --OCH(CH₃)--) 1.22-1.64 (4H, multiplet, --CH₂ CH(CH₃)₂)1.64-1.90 (2H, multiplet, --CH(CH₃)₂) 3.32 (4H, singlet, --OH) 3.45-4.02(10H, multiplet, --CHOCH₂ --, --CH--O--)

MASS (FD): 351 (M+1)

Example 1-15 Synthesis of1,6-di-O-(1,3-dimethylbutyl)-di-O-methyl-O-(1,3-dimethylbutylidene)sorbitolCompound (15)!

In a 1-liter reaction vessel equipped with a thermometer, a refluxcondenser, a dropping funnel, and a stirrer, 15.6 g (0.39 mol) of sodiumhydride (content: 60%, oily) was placed. The sodium hydride was washedwith 100 ml of hexane by decantation. To the vessel, 200 ml of toluenewas added and stirred, to which 64.1 g (0.15 mol) of Compound (13b)obtained in Example 1-13 dissolved in 100 ml of toluene was addeddropwise over 15 minutes at room temperature. The mixture was furtherstirred for 1 hour at 100° C. After the mixture was cooled to 40° C.,49.1 g (0.39 mol) of dimethyl sulfate was added dropwise over 1 hourwith the temperature maintained below 60° C. After the mixture wasfurther stirred for 1 hour at 60° C. and cooled, 156 g of 10% aqueoussolution (0.39 mol) of sodium hydroxide was added and the mixture wasstirred at 70° to 80° C. for 1 hour. After cooling, the mixture wasallowed to phase separate. The water layer was extracted twice with 150ml of diethyl ether, and the organic layer was combined with etherextracts. The mixture was washed three times with 100 ml of saturatedbrine, dried over anhydrous sodium sulfate, and evaporated to distillaway the solvent to give 68.0 g of viscous oily substance. The substanceobtained was purified by silica gel column chromatography using ahexane/diethyl ether 95/5-90/10 (vol/vol)! developing solvent. As aresult, 56.6 g of Compound (15) was obtained, The purity determined bygas chromatography was 97.7%.

IR (NEAT, cm⁻¹): 2956, 2878 (C-H stretching), 1470, 1374 (C-Hdeformation), 1125, 1095 (C-O stretching)

¹ H NMR (CDCl₃, δppm): 0.70-1.08 (18H, --CH₂ CH(CH₃)₂) 1.08-1.30 (9H,--OCH(CH₃)CH₂ --, (--O--)₂ C(CH₃)CH₂ --) 1.30-1.67 (6H, --OCH(CH₃)CH₂--, (--O--)₂ C(CH₃)CH₂ --) 1.67-1.96 (3H, --CH(CH₃)₂) 3.22-4.25 (16H,--O--CH₂ --, --O--CH--, --OCH₃)

Example 1-16 Synthesis of a mixture of2,3,4,5-tetra-O-methyl-1,6-di-O-(1,3-dimethylbutyl)sorbitol,2,4,5-tri-O-methyl-1,3,6-tri-O-(1,3-dimethylbutyl)sorbitol,1,6-di-O-(1,3-dimethylbutyl)-di-O-methyl-O-(1,3-dimethylbutylidene)sorbitol,O-methyl-1,3,6-tri-O-(1,3-dimethylbutyl)-O-(1,3-dimethylbutylidene)sorbitol,2,3,4,5,6-penta-O-methyl-1-O-(1,3-dimethylbutyl)sorbitol, anddi-O-methyl-1,3,6,x-tetra-O-(1,3-dimethylbutyl)sorbitol Compounds (16c)!

1) Ketals formed from sorbitol and methyl isobutyl ketone: Compounds(16a)

In a 3-liter reaction vessel equipped with a thermometer, a refluxcondenser, a Dean and Stark trap, a calcium chloride tube, and astirrer, 363.76 g (1.997 mol) of D-sorbitol, 1200 g (11.981 mol) ofmethyl isobutyl ketone, 18.99 g (0.0998 mol) of p-toluene sulfonic acid1 hydrate, and 300 ml of hexane were placed and heated with stirring. Areaction was carried out at a temperature of from 93° to 95° C. for 5hours while distilling off 60% of a predetermined amount of water. Afterbeing cooled to 60° C., the reaction mixture was neutralized by adding21.16 g (0.1996 mol) of sodium carbonate, and stirred at 60° C. for 30minutes. After 200 g of water was added to the mixture and stirred at60° C. for 30 minutes, the mixture was allowed to stand to separate intotwo layers. After the lower layer was discarded, the remaining mixturewas washed with 200 g of saturated brine, and evaporated to give 544.6 gof crude Compounds (16a). The obtained crude Compounds (16a) wassubjected to a reduced-pressure distillation and a forerun wasdiscarded. 486.2 of the residue obtained was subjected to an adsorptiontreatment by passing through 24.31 g (5% by weight to the residue) ofactivated clay on a filter (PTFE, 0.2 μm) under pressure. As a result,471.3 g of Compounds (16a) was obtained (yield: 55.1%). The purity ofCompounds (16a) as determined by gas chromatography was 95% includingboth diketal and triketal; diketal/triketal=33/67 (weight ratio)!.

2) Hydrogenated compounds of ketals formed from sorbitol and methylisobutyl ketone: Compounds (16b)

In a 1-liter autoclave, 450 g (1.120 mol) of Compounds (16a) obtainedabove, which was sufficiently dehydrated, and 9.0 g (2% by weight) of 5%Pd/C catalyst were placed, the 5% Pd/C catalyst being prepared by dryinga commercially available product with 50% moisture content (5% Pd carbonpowder with 50.0% moisture content, E-type, pH 6.0, manufactured by N.E. Chemcat Corp.) at room temperature for one day under a reducedpressure using a vacuum pump. The temperature of the autoclave wasraised with stirring the mixture under a hydrogen pressure of 20 kg/cm².Then the mixture was kept for 20 hours under a hydrogen pressure of 200kg/cm² at 190° C. After the completion of the reaction, the mixture wasdissolved in 200 ml of hexane, and subjected to a pressure-filtrationthrough a membrane filter (PTFE, 0.2 μm). Hexane in the filtrate wasdistilled away to give 433 g of a crude Compounds (16b) (yield of thecrude compounds: 95%).

The purity of the compounds obtained was determined to be 90% by gaschromatography (including dialkyl ether, trialkyl ether, dialkyl ethermonoketal, trialkyl ether monoketal, monoalkyl ether, and tetraalkylether; weight ratio of the components: dialkyl ether:trialkylether:dialkyl ether monoketal:trialkyl ether monoketal:monoalkylether:tetraalkyl ether=63.5:16.0:14.7:2.9:2.7:0.2; hydroxylvalue=444.5).

3) A mixture of2,3,4,5-tetra-O-methyl-1,6-di-O-(1,3-dimethylbutyl)sorbitol,2,4,5-tri-O-methyl-1,3,6-tri-O-(1,3-dimethylbutyl)sorbitol,1,6-di-O-(1,3-dimethylbutyl)-di-O-methyl-O-(1,3-dimethylbutylidene)sorbitol,1,6,x-tri-O-(1,3-dimethylbutyl)-O-methyl-O-(1,3-dimethylbutylidene)sorbitol,2,3,4,5,6-penta-O-methyl-1-O-(1,3-dimethylbutyl)sorbitol, anddi-O-methyl-1,3,6,x-tetra-O-(1,3-dimethylbutyl)sorbitol: Compounds (16c)

In a 2-liter reaction vessel equipped with a thermometer, a refluxcondenser, a dropping funnel, and a stirrer, 28.5 g (1.19 mol) of sodiumhydride powder and 900 ml of toluene were placed. 100 g (0.79 mol ashydroxyl group) of Compounds (16b) obtained in 2) above was dissolved in100 ml of toluene, and added dropwise to the vessel over 30 minutes withstirring under nitrogen atmosphere. Then 50 ml of toluene was added tothe vessel. The reaction mixture was heated to 110° C. and refluxed withstirring for 1 hour at 110° C. After the mixture was cooled to 50° C.,149.9 g (1.19 mol) of dimethyl sulfate was added dropwise over 1 hourwith the temperature maintained at 50° C. 300 ml of toluene was addedand the mixture was matured for 1 hour at 80° C. After the mixture wascooled and 476 g of 10% aqueous solution (1.19 mol) of sodium hydroxidewas added, the mixture was stirred at 70° to 80° C. for 30 minutes. Themixture was cooled to room temperature and allowed to stand to phaseseparate. The lower layer was discarded. The upper toluene layer waswashed 4 times with saturated brine, dried over anhydrous sodiumsulfate, and evaporated to give 98.4 g of viscous oily substance,Compounds (16c) (yield: 89%). The purity of the substance was determinedto be 90% by gas chromatography. The composition of the substance was asfollows: 56.8% by weight of2,3,4,5-tetra-O-methyl-1,6-di-O-(1,3-dimethylbutyl)sorbitol, 14.3% byweight of 2,4,5-tri-O-methyl-1,3,6-tri-O-(1,3-dimethylbutyl)sorbitol,3.2% by weight of1,6-di-O-(1,3-dimethylbutyl)-di-O-methyl-O-(1,3-dimethylbutylidene)sorbitol,2.6% by weight of1,3,6-tri-O-(1,3-dimethylbutyl)-O-methyl-O-(1,3-dimethylbutylidene)sorbitol,2.4% by weight of2,3,4,5,6-penta-O-methyl-1-O-(1,3-dimethylbutyl)sorbitol, and 2% byweight of di-O-methyl-1,3,6,x-tetra-O-(1,3-dimethylbutyl)sorbitol

IR (NEAT, cm⁻¹): 2956, 2878, 2830 (C-H stretching), 1470, 1374, 1350(C-Hdeformation), 1110 (C-O stretching)

Example 2-1

With respect to each of the oils used in the present inventive productsand comparative products, kinematic viscosities at 40° C. and 100° C.were measured in accordance with JIS K-2283. The results are shown inTables 1 and 2.

                                      TABLE 1                                     __________________________________________________________________________    No. of Oil                                   Kinematic Viscosity                                                                      Fluidity              for Inventive                                (mm.sup.2 /s)                                                                            at Low                Product                                                                              Compound Structure                    40° C.                                                                       100° C.                                                                     Temperature           __________________________________________________________________________    (6)                                                                                   ##STR19##                            27.03 4.62 Fluid                 (7)                                                                                   ##STR20##                            56.61 7.20 Fluid                 (8)                                                                                   ##STR21##                            16.37 3.16 Fluid                        (Ether alkyl groups, except for those at both ends, may be                    arranged at                                                                   random or in block form.)                                              __________________________________________________________________________     Note: The parenthesized figures correspond to the numbers for oils in         Examples 11 to 116.                                                      

                                      TABLE 2                                     __________________________________________________________________________    No. of Oil                                    Kinematic                                                                                Fluidityy            for Inventive                                 (mm.sup.2 /s)                                                                            at Low               Product   Compound Structure                  40° C.                                                                       100° C.                                                                     Temperature          __________________________________________________________________________    (11)                                                                                     ##STR22##                          11.55 2.39 Fluid                (12)                                                                                     ##STR23##                          11.73 2.61 Fluid                (M-1)     (6) 67% by weight + (7) 33% by weight                                                                             35.29 5.37 Fluid                (8-1)     Synthesized according to Example 1-8-1.                                                                           24.36 4.20 Fluid                (8-2)     Synthesized according to Example 1-8-2.                                                                           45.41 6.22 Fluid                (16c)     Synthesized according to Example 1-16.                                                                            11.94 2.62 Fluid                Oil (1) for                                                                             Naphthene oil                       30.0  4.4  Fluid                Comparative Product                                                           __________________________________________________________________________

Example 2-2

With respect to each of the oils used in the present inventive productsand comparative products, fluidity at low temperatures was measured.Specifically, oil samples used in Example 2-1 were placed in a constanttemperature vessel maintained at -20° C. for 1 hour, and observedwhether or not the samples showed fluidity. The results are shown inTables 1 and 2.

Example 2-3

Each of inventive products and comparative products was prepared, eachbeing a composition consisting of 1,1,1,2-tetrafluoroethane (HFC134a)and one of the oils for inventive and comparative products listed inTables 3 and 4, and the compatibility between the hydrofluorocarbon andthe oil was evaluated. Specifically, the two-phase separationtemperature for 1,1,1,2-tetrafluoroethane at low temperatures wasmeasured at sample oil concentrations of 10 vol %, 20 vol %, 30 vol %,and 40 vol %. The results are shown in Tables 3 and 4.

As is evident from Tables 3 and 4, the oils used in the inventiveproducts had a better compatibility with HFC134a than those used in thecomparative products.

                                      TABLE 3                                     __________________________________________________________________________                                                Separation Temperature            No. of Oil                                  at Low Temperature                                                            (°C.)                      for Inventive                               10                                Product                                                                             Compound Structure                    vol %                                                                             20 vol %                                                                           30 vol                                                                             40 vol              __________________________________________________________________________                                                              %                    (6)                                                                                 ##STR24##                            -56 -52  -51  -52                 (15)                                                                                 ##STR25##                            -48 -39  -34  -39                       (Ether alkyl groups, except for those at both ends, may be arranged           at                                                                            random or in block form.)                                               (11)                                                                                 ##STR26##                            <-70                                                                              <-70 <-70 <-70                      (Ether alkyl groups, except for those at both ends, may be arranged           at                                                                            random or in block form.)                                               __________________________________________________________________________

                                      TABLE 4                                     __________________________________________________________________________    No. of Oil                                     Separation Temperature         for                                            at Low Temperature                                                            (°C.)                   Inventive                                      10  20  30  40                 Product                                                                             Compound Structure                       vol %                                                                             vol %                                                                             vol                                                                               vol                __________________________________________________________________________                                                               %                  (12)                                                                                 ##STR27##                               <-70                                                                              <-70                                                                              -69 <-70               M-1                                                                                  ##STR28##                                 -18                                                                               -12                                                                             -16   -26              (16c) Synthesized according to Example 1-16    <-70                                                                              <-70                                                                              <-70                                                                              <-70               Oil (1) for                                                                         Naphthene oil                            >20 >20 >20 >20                Comparative                                                                   Product                                                                       __________________________________________________________________________

Example 2-4

Each of the present inventive products was tested for the thermalstability by a sealed tube test.

Specifically, 10 g of an oil with a moisture content adjusted below 20ppm and 5 g of HFC134a were placed in a glass tube. After iron, copper,and aluminum were added thereto as catalysts, the glass tube was sealed.After tested at 175° C. for 14 days and 28 days, the composition of oiland HFC134a was observed for its appearance and presence ofprecipitation. After HFC134a was removed, the acid value of oil wasmeasured. The results are shown in Tables 5 and 6.

As is evident from Tables 5 and 6, the thermal stability of theinventive products was good, all of the inventive products showing noabnormality in appearance, and no precipitation.

                                      TABLE 5                                     __________________________________________________________________________    No. of                                                 Acid Value             Oil for                                                (mgKOH/g)              Inventive                                Test      Precipi-                                                                          Before                                                                             After             Product                                                                            Compound Structure                  Period                                                                            Appearance                                                                          tation                                                                            Test Test              __________________________________________________________________________    (11)                                                                                ##STR29##                                                                                                         ##STR30##                                                                         ##STR31##                                                                           ##STR32##                                                                         ##STR33##                                                                          ##STR34##             (Ether alkyl groups, except for those at both ends, may be arranged           at                                                                            random or in block form.)                                                (12)                                                                                ##STR35##                                                                                                         ##STR36##                                                                         ##STR37##                                                                           ##STR38##                                                                         ##STR39##                                                                          ##STR40##        __________________________________________________________________________

                                      TABLE 6                                     __________________________________________________________________________    No. of                               Acid Value                               Oil for                              (mgKOH/g)                                Inventive              Test      Precipi-                                                                          Before                                                                            After                                Product                                                                            Compound Structure                                                                              Period                                                                            Appearance                                                                          tation                                                                            Test                                                                              Test                                 __________________________________________________________________________    (8-2)                                                                              Synthesized according to Example 1-8-2.                                                         14 days                                                                           Normal                                                                              None                                                                              <0.05                                                                             <0.05                                                       28 days                                                                           Normal                                                                              None                                                                              <0.05                                                                             <0.05                                (16c)                                                                              Synthesized according to Example 1-16.                                                          14 days                                                                           Normal                                                                              None                                                                              <0.05                                                                             <0.05                                                       28 days                                                                           Normal                                                                              None                                                                              <0.05                                                                             <0.05                                __________________________________________________________________________

Example 2-5

Each of the present inventive products and a comparative product weretested for the hydrolysis resistance by a sealed tube test.

Specifically, 10 g of an oil with a moisture content adjusted at 3000ppm, and 5 g of HFC134a were placed in a glass tube. After iron, copper,and aluminum were added thereto as catalysts, the glass tube was sealed.After tested at 175° C. for 14 days, the composition of oil and HFC134awas observed for its appearance and presence of precipitation. After thehydrofluorocarbon was removed, the acid value of oil was measured. Theresults are shown in Tables 7 and 8. As is evident from Tables 7 and 8,the hydrolysis resistance of the inventive products was good, withshowing no abnormality in appearance, no precipitation, and, unlike thecomparative product using an ester, no increase in the acid value.

                                      TABLE 7                                     __________________________________________________________________________                                             Sealed Tube Test                     No. of                                             Acid Value                 Oil for                                            (mgKOH/g)                  Inventive                                      Precipi-                                                                          Before                                                                            After                  Product                                                                            Compound Structure                  Appearance                                                                          tation                                                                            Test                                                                              Test                   __________________________________________________________________________    (11)                                                                                ##STR41##                          Normal                                                                              None                                                                              <0.05                                                                             <0.05                       (Ether alkyl groups, except for those at both ends, may be arranged           at random or in block form.)                                             (12)                                                                                ##STR42##                          Normal                                                                              None                                                                              <0.05                                                                             <0.05                  __________________________________________________________________________

                                      TABLE 8                                     __________________________________________________________________________                                Sealed Tube Test                                  No. of                                Acid Value                              Oil for                               (mgKOH/g)                               Inventive                         Precipi-                                                                          Before                                                                            After                               Product   Compound Structure                                                                              Appearance                                                                          tation                                                                            Test                                                                              Test                                __________________________________________________________________________    (8-2)     Synthesized according to Example 1-8-2.                                                         Normal                                                                              None                                                                              <0.05                                                                             <0.05                               (16c)     Synthesized according to Example 1-16.                                                          Normal                                                                              None                                                                              <0.05                                                                             <0.05                               Oil (2) for                                                                             Trimethylolpropane tricaproate.                                                                 Normal                                                                              None                                                                              0.05                                                                              7.3                                 Comparative Product                                                           __________________________________________________________________________

Example 2-6

With respect to each of the oils used in the present inventive productsand comparative products, volume resistivity at 25° C. was measured inaccordance with JIS C-2101. The results are shown in Tables 9 and 10.

As is evident from Tables 9 and 10, the oils used in the inventiveproducts had better volume resistivity than those used in thecomparative products.

                                      TABLE 9                                     __________________________________________________________________________    No. of Oil                                  Volume                            for Inventive                               Resistivity                       Product                                                                             Compound Structure                    (Ω· cm)            __________________________________________________________________________    (15)                                                                                 ##STR43##                            2.0 × 10.sup.14                   (Ether alkyl groups, except for those at both ends, may be arranged           at random or in block form.)                                            (11)                                                                                 ##STR44##                            2.1 × 10.sup.12             (12)                                                                                 ##STR45##                            2.0 × 10.sup.13             __________________________________________________________________________

                                      TABLE 10                                    __________________________________________________________________________    No. of Oil                            Volume                                  for Inventive                         Resistivity                             Product                                                                             Compound Structure              (Ω · cm)                 __________________________________________________________________________    (8-2) Synthesized according to Example 1-8-2.                                                                       9.9 × 10.sup.13                   (16c) Synthesized according to Example 1-16.                                                                        9.4 × 10.sup.13                    ##STR46##                                                                           ##STR47##                      2.0 × 10.sup.11                   Oil (4) for                                                                         Unirube MB-11 (MW1000)          5.0 × 10.sup.9                    Comparative                                                                         (Polyoxypropylene glycol monobutyl ether)                               Product                                                                       Oil (5) for                                                                         Propyleneoxide-1,2-epoxybutane copolymer with methyl ethers at both           ends                            .sup. 1.3 × 10.sup.10             Comparative                                                                         (MW1245)                                                                Product                                                                       __________________________________________________________________________

Example 2-7

Each of the present inventive products, each comprising ahydrofluorocarbon and a refrigeration oil containing an ether compoundused in the present invention and additives, was tested for the thermalstability, etc. by a sealed tube test.

Specifically, 10 g of an oil with a moisture content adjusted at 3000ppm and 5 g of HFC134a were placed in a glass tube. After iron, copper,and aluminum were added thereto as catalysts, the glass tube was sealed.After tested at 175° C. for 14 days, the composition of oil and HFC134awas observed for its appearance and presence of precipitation. AfterHFC134a was removed, the moisture content of the oil was measured. Theresults are shown in Table 11. As is evident from Table 11, the thermalstability of the inventive products was good, with all of the inventiveproducts showing no abnormality in appearance, and no precipitation.Also, a good dehydration could be achieved.

While the invention has been described in detail and with reference tospecific embodiments thereof, it will be apparent to one skilled in theart that various changes and modifications can be made therein withoutdeparting from the spirit and scope thereof.

                                      TABLE 11                                    __________________________________________________________________________                                                      Water Content                                                                 (ppm)                       Inventive              Additives              Precipi-                                                                          Before                                                                            After                   Product                                                                            Ether Used in the Present Invention                                                             (Amount*.sup.1)  Appearance                                                                          tation                                                                            Test                                                                              Test                    __________________________________________________________________________    A-1  (8-2)             1,3-dicyclohexylcarbbdiimide                                                                 (3)                                                                             Normal                                                                              None                                                                              3000                                                                              212                          Synthesized according to Example 1-8-2.                                  A-2  (15)              1,3-dicyclohexylcarbodiimide                                                                 (3)                                                                             Normal                                                                              None                                                                              3000                                                                              198                     A-3   (6)              1,1-bis(2-methylpropoxy)-                                                                    (3)                                                                             Normal                                                                              None                                                                              3000                                                                              154                                            cyclohexane                                            A-4   (6)              Glycidyl 2-ethylhexanoate                                                                    (3)                                                                             Normal                                                                              None                                                                              3000                                                                              645                     A-5  (12)              3,4-epoxycyclohexylmethyl                                                                    (3)                                                                             Normal                                                                              None                                                                              3000                                                                              312                                            3,4-epoxycyclohexanecarboxylate                        __________________________________________________________________________     *.sup.1 Parts by weight based on 100 parts by weight of the ether used in     the present invention.                                                   

What is claimed is:
 1. A working fluid composition for a refrigeratingmachine, comprising a hydrofluorocarbon and a refrigeration oilcontaining as a base oil a polyol ether derivative represented by thefollowing formula (XIII_(AA)) or (XIII_(BB)): ##STR48## wherein R¹ to R⁶may be identical or different, each representing a linear alkyl grouphaving 1-14 carbon atoms, a branched alkyl group having 3-14 carbonatoms or a cyclic alkyl group having 3-14 carbon atoms; R⁷ represents anhydrogen atom, or a linear alkyl group having 1-13 carbon atoms, abranched alkyl group having 3-13 carbon atoms or a cyclic alkyl grouphaving 3-13 carbon atoms; R⁸ represents a linear alkyl group having 1-13carbon atoms, a branched alkyl group having 3-13 carbon atoms or acyclic alkyl group having 3-13 carbon atoms; R⁷ and R⁸ may together jointo form a ring with an alkylene group having 2-13 carbon atoms; thetotal number of carbon atoms is 8-40 for R¹, R², R³, R⁶, R⁷ and R⁸ informula (XIII_(AA)), and for R¹, R⁴, R⁵, R⁶, R⁷ and R⁸ in formula(XIII_(BB)), and is 1-13 for R⁷ and R⁸ in formulas (XIII_(AA) andXIII_(BB)); and the specific structures within the parenthesis may bearranged in any sequential order.
 2. The working fluid composition for arefrigerating machine according to claim 1, wherein a hexahydric alcoholresidue of the compound represented by formula (XIII_(AA)) or(XIII_(BB)) is derived from sorbitol.
 3. The working fluid compositionfor a refrigerating machine according to claim 1 or 2, wherein thecompound represented by formula (XIII_(AA)) or (XIII_(BB)) issynthesized by the steps of:reacting a hexahydric alcohol represented bythe following formula (V): ##STR49## with (a) one or more carbonylcompounds represented by the following formula (XII) for ketalization oracetalization: ##STR50## wherein R⁷ represents a hydrogen atom, a linearalkyl group having 1-13 carbon atoms, a branched alkyl group having 3-13carbon atoms or a cyclic alkyl group having 3-13 carbon atoms, and R⁸represents a linear alkyl group having 1-13 carbon atoms, a branchedalkyl group having 3-13 carbon atoms, or a cyclic alkyl group having3-13 carbon atoms with the proviso that R⁷ and/or R⁸ have at least onehydrogen atom at α-position to the carbonyl group, and the total numberof carbon atoms of R⁷ and R⁸ is 1-13; and R⁷ and R⁸ may together join toform a ring with an alkylene group having 2-13 carbon atoms; or with (b)reactive derivatives of said carbonyl compounds thereof fortransketalization or transacetalization to obtain a cyclic ketal or acyclic acetal; hydrogenating the cyclic ketal or the cyclic acetal toobtain a polyol ether ketal or a polyol ether acetal; and alkylating thepolyol ether ketal or the polyol ether acetal.
 4. The working fluidcomposition for a refrigerating machine according to claim 1 or 2, whichfurther comprises one or more compounds selected from the groupconsisting of (a) 0.05 to 2.0 parts by weight of an epoxy compound, (b)0.01 to 100 parts by weight of an orthoester compound, (c) 0.01 to 100parts by weight of an acetal or a ketal, and (d) 0.05 to 5 parts byweight of carbodiimide, each amount of (a) to (d) being based on 100parts by weight of the polyol ether derivative represented by formula(XIII_(AA)) or (XIII_(BB)).
 5. The working fluid composition for arefrigerating machine according to claim 3, which further comprises oneor more compounds selected from the group consisting of (a) 0.05 to 2.0parts by weight of an epoxy compound, (b) 0.01 to 100 parts by weight ofan orthoester compound, (c) 0.01 to 100 parts by weight of an acetal ora ketal, and (d) 0.05 to 5 parts by weight of carbodiimide, each amountof (a) to (d) being based on 100 parts by weight of the polyol etherderivative represented by formula (XIII_(AA)) or (XIII_(BB)).
 6. Theworking fluid composition for a refrigerating machine according to claim1, wherein said polyol ether derivative has an average molecular weightin the range of from 200 to
 800. 7. The working fluid composition for arefrigerating machine according to claim 1, wherein said polyol etherderivative has an average molecular weight in the range of from 300 to700.
 8. The working fluid composition for a refrigerating machineaccording to claim 1, wherein said polyol ether derivative has aviscosity at 100° C. of from 0.5 to 30 mm² /s.
 9. The working fluidcomposition for a refrigerating machine according to claim 1, whereinsaid polyol ether derivative has a viscosity at 40° C. of from 1 to 300mm² /s.